13 years of experience in manufacturing continuity buzzers. High Volume Black Type Continuity Buzzer Overview: Energy-saving continuity buzzer Long battery life No "operation indicator lamp" that consumes battery power Operation: The buzzer sounds when short-circuited. Sound Pressure Level: 90dB / 1m (manufacturer's specification) Batteries: 2 AAA batteries [Batteries not included] Clip: Medium-sized clip Size that doesn't get in the way even when put in a pocket Usable from low-voltage cables to weak-current cables Clips up to 22□ (maximum 38□) Wire Used: UL1007 AWG20 Red/Black Dimensions: Length: approx. 90mm Width: approx. 30mm Thickness: approx. 21mm Weight: Approx. 29g (without batteries) Power Switch: Built-in to the main unit Operation Confirmation Range: Short-circuit test of AE-0.9mm 2c 200m (There is a 400m return) We have confirmed that the volume does not change and it operates.