How to Tell if Pin Box is Lippert 1621 for Replacement Curt Flex Air 5th Wheel Pin Box Fitment

Question:

Im interested in the Trailair Flex Air. Ive been told by the RV place that I have a Lippert 1621 pin box, but Id like to confirm that for myself that Trailair is HEAVY, and would be way expensive to return ship if it doesnt fit!! How do I confirm which pinbox I actually have? Is there a measurement I can take? Thanks for your help!

asked by: Tim C

Expert Reply:

To confirm whether or not you have a Lippert 1621 pin box that the Curt Flex Air 5th Wheel Pin Box # LC369535 would replace, you need to look at the stickers on the side of the pin box for that "1621" number. If you can't find it or you find a different number and you still want to check the measurements you can still do so.

I've attached a review video of the Flex Air pin box as well as a link to our helpful article that goes over the different measurements you can take to verify which pin box number you have.

expert reply by: Jon G