The STEELMAN 97202 Wireless ChassisEAR is a unique diagnostic device specifically designed to pinpoint squeaks. rattles. and any other troublesome and errant noises in a variety of locations across a vehicle's engine. axles. and chassis. Ideal for diagnosing faulty fuel injectors. bearings. gears. suspensions. transmissions. differentials and CV joints. and under hoods. Working as a high powered wireless stethoscope for your car or truck. each of the 4 independent transmitters can be placed in a separate location around the vehicle using the built-in clips and magnets or the included nylon hook-and-loop straps. These then transmit to the receiver allowing you to listen to the vehicle during standard operation to hear noises that are difficult or just impossible to duplicate in a repair stall. Each transmitter is assigned its own channel on the receiver and can be selected or muted individually to make pinpointing the location and cause of a noise easy. With a 50-foot range from transmitter to receiver. the ChassisEAR is useable on all makes and models of cars and light trucks. as well as a variety of larger vehicles. Included in the kit are: 4 transmitters. 1 receiver unit. 1 set of mini earphones. 4 cable-leads/microphone clamps. 12 nylon straps. 12 hook-and-loop straps. 6 AA batteries. 16 AAA batteries. an organizer pouch. location identifier note pad. instruction manual. and a blow-molded storage case.