It captures subtle sounds through walls, ideal for detecting broken pipes and locating leaks. Features: High-sensitivity metal probe and detector. Includes earphone. Compact and lightweight for easy carrying. Simple operation: attach to doors, windows, or walls, then adjust the volume until a clear sound is heard. Capable of transmitting sound through wooden, brick, walls, windows, doors, and metal surfaces. Can be used as a recording pen. Specifications: Color: Black Current consumption: 10mA Sensor sensitivity: -70dB Maximum o amplification: 20000X Battery: 5V, 200mAh Product size: 57 x 35mm / 2.2 x 1.4in Product weight: 25g / 0.9oz Package size: 112 x 87 x 45mm / 4.4 x 3.4 x 1.8in Package weight: 45g Packing List: 1 x Voice Listening Detector 1 x Earphone 1 x USB Cable