Depending on the type of trailer used, common connections include a variety of hitches, receiver tubes, hitch pins, ball mounts, couplers and chains. Hitches bolt to the chassis of vehicles to connect trailers and other extensions. Receiver tubes attach to the front of vehicles needing to be towed to connect to tow trucks. Hitch pins secure trailer couplers. Ball mounts and trailer couplers work together to connect trailers to tow vehicles. Chains have hooks that provide additional connection security during towing.