The Amprobe BT-250 works on powered systems from 90 to 280 VAC and is designed for use in residential and light commercial environments. Comes complete as a kit with transmitter, receiver, socket/test lead cable set with insulated alligator clips and a light fixture adapter. All housed in a professional hard carrying case. The BT-250 is a preferred solution for the latest in code requirements. Identify circuit breakers fast and efficiently. Identifies circuit breaker location. Works on all electrical systems from 90 to 280 VAC. Perfect for office, residential and HVAC applications. Automatic sensitivity adjustment. Microprocessor controlled. Extremely accurate reading always finds the right breaker. Durable and dependable. Includes light fixture adapter, socket/test lead adapter with clips and deluxe carrying case. Environment : < 2000m, indoor operation. Sensitivity : Illuminates green arrow, vibrates and beeps at 4mm (0.16) distance from a wire carrying 120 VAC