The IPA Light Ranger Mobile Universal Trailer Tester (MUTT), No. 9101, tests lights and electric brakes for utility and RV type trailers. The water-resistant and portable design allows users to test a trailer without the tow vehicle. Compatible with 7 spade, 6 round and 4/5 flat pin connection types, it can simulate all electrical circuits while providing industry standard pin configurations and short circuit protection. The tool comes with a rugged, American-made enclosure utilizing a strong carrying handle, external power accessory port and internal battery compartment that fits motorcycle-type batteries.