It can capture subtle sounds through wall which is perfect for detecting broken pipes inside wall and finding leaking locate. Features: High sense metal probe and detector. Coming with earphone. Small and light weight for easy carrying. Easy operate cling to door/window/wall adjust v-olume until you hear a clear sound. Able to get sound out from wooden/brick wall/windows/door/armor plate. Can be used as recording pen. Specifications: Color: black Cunsumption current:10mA Measuring e-lement sensitivity: -70db Highest audio enlargement multiple: 20000X Battery: 5V 200mAh Item size: 57 * 35mm / 2.2 * 1.4in Item weight: 25g / 0.9ounce Package size: 112 * 87 * 45mm / 4.4 * 3.4 * 1.8in Package weight: 45g Packing List: 1 * Voice Listen Detector 1 * Earphone 1 * USB Cable