RV Square Bumper for Bike Cargo Carrier Hitch Receiver Adapter Mount on RV Travel Trailer Compatible with Coachman for 4" Square Continuous Welded RV Bumper (Also fits Bumper 4.5" Tall x 4.25" deep). Red Hound Auto Premium RV Bumper Receiver Adapter Size: 2 inch receiver For 4" square continuous welded RV bumpers (also fits bumpers 45" tall x 425" deep) Constructed of black powder coated steel with zinc plated hardware Designed for bike racks, NOT for towing purposes