This Bump-It™ receiver adaptor with square post brings transferability of bicycles from the Jack-It® A-frame travel trailer mount two bike carrier to the vehicle hitch. Simply remove and reattach the V-Wing bike mounting section of the Jack-IT® PLUS (B00338) and Jack-IT® Original (429756) carrier models to the hitch receiver of a motorized vehicle. Specifications Receiver adaptor for bike carriers, compatible fit with square post design on Jack-IT PLUS (B00338) and Jack-IT Original (429756) carrier models only, sold separately 40 lbs per bike load rating 22.5" overall length with 17" of inside bike clearance Fits 1.25in and 2in hitches; includes aluminum 2in adapter Includes NoMotion™ pin for stable and quiet hitch connection. Rated for use on motorized vehicles only including passenger and motorized RV