This thermal circuit breaker can detect abnormal conditions such as overload, undervoltage, and short circuit, and automatically cut off the circuit in these situations to save your fuses 125VAC/250VAC, 32VDC, 50-60Hz; Dielectric strength: 1500VAC for 1 minute; Leakage current: ≤0.5mA; Insulation resistance: ≥100MΩ at 500VDC for 1 minute; Rated short-circuit capacity: 125VAC/1000A, 250VAC/1000A Simply insert the terminals of this HVAC circuit tester into the fuse socket to test the circuit breaker. After automatic , just the reset button on the top of the circuit breaker to reset and resume normal use The thermal overload protector is universally compatible with all HVAC and electrical equipment, including central air conditioning systems, residential and commercial appliances, as well as any control boards using ATC 3-amp or 5-amp fuses (Rated 32V DC, 125/250V AC) Color: As shown Material: plastic Package Contents: 2pcs * Push Button Manual Reset Circuit Breaker Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.