What Info is Needed to Pick Out Sidewinder Pin Box for Trailer

Updated 07/24/2025 | Published 07/19/2025

Question:

I am looking to purchase your Reese Sidewinder 20K. Your installation video said i can send you a copy of my current kingpin label, to ensure compatibility and bolt pattern.

asked by: Mike

Expert Reply:

Hey Mike, yes if you can get us the pin box model that you have now I can see which Sidewinder you'd need. This can be determined by the info that's on the pin box like you said or if you let me know what RV you have I can see if we already have figured out what pin box it has.

expert reply by: Jameson C

Michael P.

7/24/2025

Jameson, I just ordered your Reese Sidewinder RP34FR. My current Kingpin is a Lippert 1621, and my hitch is a B&W companion. Do I need anything special? adapter plates, etc? In addition, I "might" upgrade my RV soon, and it has a Lippert "Rhino box" King Pin., and I believe the FP34FR is still compatible with it. Anything special I would need for it? Many thanks for your great support always! r/Mike

Jameson C.

7/24/2025

@MichaelP You are definitely on the right track and yes the Reese Sidewinder part #RP34FR is correct since you have the 1621 pin box. Since you have a B and W Companion hitch you also would need the custom wedge part # SWW-06 for them to fit together the easiest. Also the Sidewinder you went with is also compatible with the Rhino box so you can take it with you to your next RV as well.