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  1. Tonneau Cover
  2. BAK Industries
  3. Fold-Up - Hard
  4. Flush Profile - Inside Bed Rails
  5. Rack Compatible
  6. Aluminum
BAKFlip MX4 Hard Tonneau Cover - Folding - Aluminum - Matte Finish
BAK Industries

BAKFlip MX4 Hard Tonneau Cover - Folding - Aluminum - Matte Finish

Part Number: BAK48122
In Stock
$1,299.99
Retail:$1,399.99
You Save: $100.00
Tonneau Cover

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In Use/Installed

Get style and versatility with this heavy-duty, all-aluminum tonneau. Quad-fold cover sits inside your vehicle's bed rails and secures upright for unrestricted bed access. Tailgate opens and closes with cover up or down. Matte black finish. Great Prices for the best tonneau cover from BAK Industries. BAKFlip MX4 Hard Tonneau Cover - Folding - Aluminum - Matte Finish part number BAK48122 can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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  • Reviews (148)
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BAK Industries Tonneau Cover - BAK48122

Highlights

  • Custom Fit for Your Vehicle: Secures to your truck bed with model-specific clamps and hardware
  • Gear Stays Protected: Hard aluminum panels lock with the tailgate to secure your cargo.
  • Full Bed Access: Quad-fold design flips up or folds forward so you can use the whole bed.
  • Drives With Cover Up: Prop rods hold it upright when hauling or towing a 5th wheel.
  • Built to Last: 1/2" thick aluminum panels support 400 lbs and resist rust and UV damage.
  • Keeps Water Out: Rubber seals and drain system channel rain away from your bed.
Made in USA

Features to know about

Full Bed Access: Quad-Fold Design

When you need the whole bed for hauling, the BAKFlip MX4 makes it easy. The quad-fold design lets you flip the panels open one by one for partial or full access without removing the cover. Prop rods hold the folded cover upright, so you can drive with the bed completely open. Even when it’s fully folded, it only extends about 8 inches from the bulkhead, giving you maximum usable space.

All-Season Protection: Aluminum Panels with Matte Finish

Rain, sun, or snow—this cover is built to handle it. Each ½-inch-thick aluminum panel is rustproof and reinforced with a premium-density foam core for extra strength. The matte black finish resists scratches, scuffs, and UV rays, keeping it looking sharp year after year. Seals along the rails and a built-in drainage system help keep water out of the bed so your cargo stays dry.

Secure and Simple: Automatic Latching System

Once you close the tailgate, the MX4 automatically locks down to keep everything in the bed secure. The panels latch into place without the need for extra handles or keys. And because the rear seal allows the tailgate to open or close even when the cover is down, you get solid protection and easy access at the same time.

Clean Look and Easy Install: Low-Profile Inside-Rail Mounting

This cover sits flush inside the bed rails for a sleek, low-profile look that doesn’t stick out past the sides. The aircraft-grade aluminum frame rails clamp on—no drilling required—and the included bolts secure the front hinge rail in place. Since it mounts inside the rails, you can still use stake-pocket-mounted accessories or raised side rails without interference.

Strong and Versatile: Rated for 400 lbs Evenly Distributed

You can load gear or supplies on top without worry. The BAKFlip MX4 is rated to support up to 400 lbs of evenly distributed weight, thanks to its rigid aluminum panels and sturdy frame. That makes it a solid choice for work, travel, or everyday hauling when you need both protection and strength in one cover.

Specs

Material and Construction

  • Panel Material: 1/2" thick, rustproof aluminum
  • Panel Core: Premium density foam
  • Rail Material: Aircraft-grade, rustproof aluminum with black powder coat finish
  • Finish: Matte black finish resistant to scratches, scuffs, and UV rays

Design and Function

  • Cover Type: Quad-fold, hard folding tonneau cover
  • Mount Style: Inside bed rails (flush profile)
  • Opening Options: Folded, flipped up, or closed position
  • Tailgate Operation: Opens and closes with cover open or closed
  • Latch System: Automatically latching panels
  • Sealing System: Matte black rubber seals with built-in drainage system
  • Accessory Compatibility: Compatible with stake-pocket-mounted accessories and raised side rails
  • Rack Compatibility: Compatible with racks
  • Accessory Compatibility: Compatible with BakBox2 (sold separately)

Performance

  • Weight Capacity: Rated to hold up to 400 lbs of evenly distributed weight

Installation

  • Installation Type: Easy, no-drill installation
  • Mounting Method: Frame rails clamp to the inside of truck bed side rails
  • Front Hinge Rail Attachment: Included bolts secure front hinge rail to frame rails

Included Components

  • Prop Rods: Used to secure folded cover in upright position
  • Buckle System: Integrated buckle system for securing cover

Warranty and Origin

  • Warranty: 5-Year warranty
  • Country of Manufacture: Made in the USA

448122 BAK Industries BAK Flip MX4 Hard Folding Truck Bed Cover

Replaces 48122

Installation Details BAK48122 Installation instructions

This Product Fits The Following Vehicles




Ratings & Reviews

4.6

148 reviews
Review sort icon
Get style and versatility with this heavy-duty, all-aluminum tonneau. Quad-fold cover sits inside your vehicle's bed rails and secures upright for unrestricted bed access. Tailgate opens and closes with cover up or down. Matte black finish.

by:

Good quality product in easy to install.



by:

Install was smooth and got a timely note when it was completed



by:

Love the MX4 ...Took a little longer to install but looks great...



by:

Solid performance. Only issue is with the glue holding the pads is failing



by:

I really love the bakFlip cover. It locks up all my stuff when we are on the road. I really like the looks too.



by:

I own three of these on three different trucks. The two I purchased this year and last year are not as good quality as the one I purchased in 2023.For the price they are feeling pretty cheap now and parts are falling off. Latch covers and rubber par to rest the top on when folded up have fallen off on both of the covers. I will not be buying these brand covers again.



by:

the bedcover finally came in.
Few pictures
of it installed.



by:

I replace a camper shell with the tonneau cover because it is easier to remove when I want to put my pickup camper on the pickup. I am very happy with the cover and am glad I made the switch.



by:

Excellent product! Wait time was crazy but manufacturer is to blame on that one!



by:

I am a huge fan of the BAKFlip. The installation was pretty straight forward and easy. Anybody with moderate mechanical ability can install. I think it took less than 2 hours. I live in a heavy snow area and had more than 24” of snow on it at one point and the product performed flawlessly.



by:

Bought it used.. I asked if it was complete undamaged.. It arrived complete including a scratch on the inside cover.. I'm glad it wasn't on the outside cover. Shipping was quick. Installation was fairly straight forward



by:

The cover functions ok. The tailgate leaks quite a bit. The manufactured edges that where cut were sharp and not painted or treated. The weather strip along the edges has already discolored/faded. Disappointed in the fading and less than ideal sharp edges. Somewhat expected leaks, but not this much. Average at best rating, especially for the price.



by:

I installed the BAKFlip MX4 in my RAM 2500 Crewcab has the 6' 1/2 short bed, drived 300 miles now. good product, open and close the tailgate without lifting up the cover



by:

Great fit on a Ram 2500 long bed. Everything stays dry on the inside.



by:

Great tonneau cover. Fits as it should.



by:

I have been using this cover for almost a year now, and am very pleased with it. It looks and fits great, and it is secure and keeps most of the bed dry in the rain. A couple of rubber trip bits have needed some improved securing, and I used a little RTV so it was easy. I drove it across the country round trip last summer and it was perfect. I would recommend this cover for a great-looking and pretty secure cover. Finally, it is easy to fold forward when it is time to haul loads taller than the bed rails.



by:

So after a year I am still loving this bed cover. Had the fiberglass version for my 2013 F-150 and loved it as well, that's why I purchased this one for my 2019 Super Duty, it was also the first accessory I purchased for it because I was so used to my other one and knew I couldn't live without it. I never installed the drain tubes on either covers and still haven't had water get it my bed. Also the folks at etrailer are always awesome! Thanks again!



by:

Purchased this BAKFlip for my new 22 RAM Classic 1500. Installation went well, instructions were good to follow, and it fit perfectly. One of the plastic hold down clips had a manufacturer defect with excess plastic mold residue inside the clip that prevented it from properly working. I sent an online warranty claim explaining the problem, and a new clip was sent to me in a reasonable amount of time, and it worked fine. After one year of using the cover, I am very happy with it. Everything functions as it should, and it is very versatile. While it is not 100% watertight, I mostly notice a small amount of leakage around the tailgate seal after washing the truck. Under normal rainy weather, there is no leakage, and we get plenty of rain in the PNW. My four-star rating rather than a 5 star is only because of the manufacturer defect and the curling of one of the rubber cushions on the underside of one of the panels where the adhesive holding it on the edges has not held up under the hot weather (with the black color, when the sun beats down on the cover it gets pretty toasty inside the truck bed with the cover closed). I am thinking that should be an easy fix by applying some good adhesive and taping in place until the adhesive cures. Just haven't gotten around to doing it. Again, really like this cover. Would recommend it to others, and if I ever have a need for one in the future, would definitely not hesitate getting another BAKflip.



by:

Overall, I am very pleased with my BAKFlip MX4. It has held up well after 1 year. It works well and looks good. It matches my matte black accessories and trim. It was fairly easy to assemble but I did have some tight fitment issues near the cab where the cover connects to the rail. I really like the security of the hardtop and access through the tailgate. Water is generally kept out, but sometimes there are water drips near the tailgate depending on the angle parked. So this cover keeps the bed *mostly* dry.
etrailer was very fast to deliver my cover, and it came in good condition.



by:

BAKFlip MX4 is a great addition to any pickup. It allows for secure transport of material, keeping it dry in bad weather and yet readily accessible with the flip of a panel. It also keeps the weather away from your 5th wheel hitch. Can be left on when towing.



by:

The bed cover has been great so far. Followed the instructions and took my time adjusting it and it has been working well. Keeps the bed dry and looks good. I did have to order an extra kit to get enough rail clamps. Once I put the extra clamps on it feels much more secure. For 8ft beds they need atleast 8 to 10 clamps, not 6. The cover has been working in that I don’t have to uncover the whole bed to use it. I just need to open up as much as I need at the time.



by:

Ordered the BAKFlip MX4 for my son on 12/15 after calling to verify the tonneau would arrive by Christmas. Then received an email that said "Your order has been forwarded to one of our partners for direct shipment to you" and never received another shipping update or any tracking info. Finally on 12/22 I emailed Etrailer.com who told me they didn't know when I would get it. The Tonneau finally arrived on 12/29, 3 days after my son returned to California (he drove his truck, 2100 miles). He won't be back till next Christmas so I have to figure out how to return this product. I had several other buying options to get this here by Christmas, but went with Etrailer because of their reputation. This will be my last purchase from Etrailer.com.



by:

I love how this tonneau cover works. because it allows use of almost the entire bed of the truck when it's fully open. I was a little disappointed with the clamps for installing the side rails, as they didn't seem as robust as the clamps in the cover I bought for my last truck. However, I am happy with its operation, and the fact that the truck bed is a locked compartment when I lock the tailgate.



by:



by:

Product was straight forward install, thought the fit and fair is good quality. I dont like how flimsy the topper is at the back near the tail gate. You can lift up at the back even with the tailgate closed. Hope it is secure and somebody wont try and force it open seems like it would pop open without much force.


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See what our Experts say about this BAK Industries Tonneau Cover

  • Compatibility of BAKFlip MX4 Hard Tonneau Cover with Thule TracRac Sliding Ladder Rack
    The BAKFlip MX4 Hard Tonneau Cover # BAK48122 is a great tonneau cover with the inside bed rails to allow for stake pocket mounted accessories. The Thule TracRac SR Sliding Truck Bed Ladder Rack w/ Cantilever # TH43002XT-780EX will fit properly with this cover, however because it is a folding cover, you will need to slide the uprights on the ladder rack when folding the tonneau because the uprights angle inward. If you want a fixed rack that will also work with your cover, the Adarac...
    view full answer...
  • Comparing the BAKFlip F1 to the BAKFlip MX4 on 2018 GMC Sierra 3500
    The BAKFlip MX4 Hard Tonneau Cover - Folding - Aluminum - Matte Finish # BAK48122 and the BAKFlip F1 Hard Tonneau Cover - Folding - Aluminum and Fiberglass # BAK72122 are both excellent choices. The difference is the MX4 has 1/2 inch thick rustproof aluminum panels rated to hold up to 400 lbs evenly distributed. The F1 has 5/8 inch thick fiberglass-reinforced polymer panels with aluminum undersides and insulated cores for strength. The fiberglass will not heat up like the aluminum top...
    view full answer...
  • Can the BAKFlip MX4 Tonneau Cover on a 2015 Silverado 2500 Be Folded All the Way Up When Driving?
    Yes, it can Steve! The BAKFlip MX4 Hard Tonneau Cover item # BAK48122 can be folded on top of the last panel or flipped all the way up when you're towing your 5th wheel trailer. I have attached a screenshot from the instructions below that will show you exactly how to do this. The BAKFlip MX4 Hard Tonneau Cover item # BAK48122 has been confirmed to fit the 8' bed models of the 2015 Chevrolet Silverado 2500. If you have any additional questions feel free to throw them into the comment...
    view full answer...
  • Recommended Extang Trifecta 2.0 Tonneau EX92455 For 2017 Chevy 3500 Long Bed With
    From what I can find online for inside bed dimensions, I believe the following will work for you...This is based on 24 inch Bed rail height. I reached out to my contact at Extang and they said the Extang Trifecta 2.0 Soft Tonneau Cover - Folding - Vinyl # EX92455 sits about 1 inch above the rails and the lowest part of the frame is about 1/4 inch below with the exception of the clamps about 3 inches below. With a B&W Companion that fits in a gooseneck # BWRVK3500-5W, the hitch height...
    view full answer...
  • Rack For 2019 GMC Sierra 2500 With BAKFlip MX4 Tonneau Cover
    Hey Charles, The BAKFlip MX4 Hard Tonneau Cover # BAK48121 or # BAK48122 for your 2019 GMC Sierra 2500 is compatible with one one rack that will allow you to carry a couple bikes, and that's the TruXedo Elevate. The right one depends on the size of your bed: - 6-1/2' Bed: TruXedo Elevate Truck Bed Rack System # TX46NV - 8' Bed: TruXedo Elevate Truck Bed Rack System # TX66NV The Elevate will essentially give you a roof rack at the rear of your truck, and the bars are adjustable, but...
    view full answer...
  • Bike Rack that Can Attach to Top of BAK MX4 Hard Tonneau Cover
    We have bike racks like the can attach to the top of a hard tonneau cover like the very cost-effective Hollywood Racks Truck Bed Bike Carrier # HRT970. This is a bolt-on product that holds your bike at the fork that would require you to drill through the top of your tonneau. We don't have any options that attach to the stake pockets.
    view full answer...
  • TracRack Sliding Ladder Rack Compatibility with Tonneau Cover on 2017 Ford F-250
    The TracRac SR Sliding Truck Bed Ladder Rack - 1,250 lbs # TH43003XT-000 will work with the Back Revolver X2 # BAK39331, and that seems to use the same rails as the BakFlip # BAK48122 as well as others. I can't confirm a fit with anything other than the Revolver, but the TracRack SR Ladder Rack is compatible with inside the bed rails that do not overlap the side rails of the truck bed because the bed rails are covered with the sliding rack rails that fit in the stake pockets. I've attached...
    view full answer...
  • Clearance of BAK48122 Folding Tonneau Cover When Folded Up in Storage Position
    The BAKFlip MX4 Hard Folding Tonneau Cover # BAK48122 is a confirmed fit for your 2018 GMC Sierra 3500 long-bed and when folded up completely the cover's smallest panel (nearest the cab) will be all that takes up bed space. So if you measure 8-inches back from the bulkhead under the cab window that point is where the folded-up cover will extend.
    view full answer...

Do you have a question about this Tonneau Cover?


Info for this part was:

Employee Tyler C
Edited by:
Tyler C
Employee Jameson C
Expert Research:
Jameson C
Employee Adam R
Expert Research:
Adam R
Employee Dustin K
Video by:
Dustin K
Employee Hayden R
Installed by:
Hayden R
Employee Wilson B
Updated by:
Wilson B
Employee Noah M
Updated by:
Noah M
Employee Ronnie R
Written by:
Ronnie R
Employee Zach D
Video Edited:
Zach D

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