How to Determine Correct 20K Reese Goose Box For Prime Time Trailer
Updated 12/22/2025 | Published 10/27/2024
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Question:
Hey, I’m looking to get a Reese 20k goosebox for my 2021 Prime Time sanibel 3102wb and I’m having a hard time figuring out if it would fit. Do you know the answer to this?
asked by: Allen W
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Expert Reply:
Hey Allen,
We don't have any way of knowing which pin box is on your Prime Time trailer, but I can help you determine how to figure that out. There are a couple of ways to do this, the first being to find the model number on a sticker or a plate somewhere on the pin box itself.
However, if that sticker or plate is not there, the other way to find out what pin box you have is by taking a few measurements.
I have added a link below to a help article called "4 Steps to Choosing Your 5th Wheel Pin Box" and if you scroll down a bit in the article, it walks you through the measurements that are needed. That should let you know what you have, and then you can determine what you need. There's only one 20k Reese Goose Box, so it'll just depend on if you need a spacer kit.
- Lippert 1621, 0719, Rhino, or Fabex PB 600 Pin Box: Reese Goose Box # RP85FR
- Lippert 1716 Pin Box: Reese Goose Box # RP85FR & Spacer Kit # RP97FR
Product Page this Question was Asked From
Spacer Kit for Reese 20K Goose Box, Sidewinder, or 5th Airborne 5th Wheel King Pin - Wide Wingset
- Accessories and Parts
- 5th Wheel Pin Box
- Sidewinder Parts
- Fabex Pin Box
- Lippert Pin Box
- RBW Pin Box
- Reese
more information >
Featured Help Information
Instructions
Miscellaneous Media
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Jameson C.
12/22/2025
Hey Allen, were you able to find the model number or take the measurements on your Sanibel’s pin box? Knowing which one you have will make it easier to confirm if the Reese 20K Goose Box and spacer kit fit right. Your update could help others trying to match the same setup.