This circuit breaker finder quickly and easily identifies the correct circuit breaker protecting a specific electrical circuit. The r5500 also features a receptacle tester to identify faulty wiring and a gfci check button. Features ul style""margin-top0px; padding-top 5px; padding-bottom 5px;"" simply plug the transmitter into a receptacle and scan breaker box to identify the circuit detects 5 3-wire receptacle wiring faults built-in gfci receptacle check function adjustable sensitivity wheel quickly identifies breaker audible (buzzer) and visual (led) indicators assist in identification voltage range 90 to 120v ac bandwidth 47 to 63hz power supply 1 x 9v operating humidity 0 to 85% storage temperature 4 to 140°f (-20 to 60°c) dimensions - 2-3/16""w x 1-3/16""d x 4-1/8""h weight - 0.24 includes ul style""margin-top0px; padding-top 5px; padding-bottom 5px;"" receiver transmitter battery applications ul style""margin-top0px; padding-top 5px; padding-bottom 5px;"" the reed r5500 circuit breaker finder can be used in home and industrial applications where wire or cable carrying alternating current must be located repaired or replaced. The transmitter can be used as a standalone instrument to verify the proper wiring of receptacles and/or gfci receptacles are functioning correctly