This wall listeing device has a high sound sensitivity, equipped with headphones, improving the sound quality. Can be used for wooden walls, doors, windows, steel plates, floor, pipeline, etc. Easy to use, just close to doors, windows or walls, and listen to all sounds easily in . You can adjust the volume slowly, hear a clear sound, and 't cause discomfort to your ear. It can be used anywhere, and has a built-in lithium battery, convenient to use and carry. Battery Capacity:180mAh Colour:black Material:plastic Package Contents: 1 x leak detector 1 x USB Cable 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.