"Ideal for "Vehicle Covers, Tools, Power Cords, Disposal Items and More. Gear Travels Snugged-In Behind Your Vehicle. Rugged HDTP Polyethylene with Rubber Sealed Lid. Lockable with Key. Mounts to any 3.5""- 4.5" RV Bumper with Vehicle BackPack’s Exclusive “Bolt-On” Receiver. No Drilling! Machined-in “Wobble Stop” with Lockable Pin Eliminates Movement in Receiver. All Mounting Hardware Included. Kit Includes Bolt-On Receiver, H5 Extension and Large or Extra Large Cargo Trunk. Choose Size Below.