Effectively checks cable integrity, wire continuity, PCB board connection, and product functionality with 20mA loop current during measurement Powered by an included 9V battery with easy access compartment for quick replacement, consuming none power when not in use for efficient This continuity tester features both buzzer ( 100dB) and visual LED indicators to clearly show wire connectivity condition when touching both ends of a tested wire Never use when the product is powered on or connection to live circuits to potential hazards during testing operations Crafted from ABS with portable dimensions ( 8x5.7x3.2cm / 3.15x2.24x1.26in), ideal for electricians and DIYer electrical projects, Manufacturer: HZBB