1. STRONG PENETRATION: High sensitivity sensing head using new components and advanced technology, so that the penetration increased by several times, greatly improving the sound quality, carefully and slowly adjust frequency, so as not to cause discomfort to the ear plugs. 2. SOUND SENSITIVITY: High sensitivity metal alignment with headphones improves sensitivity and sound quality, high sensitivity detects sound from wall, window, doors or armor plate with headphones for clear sound quality. 3. APPLICATIONS: 3.5 mm headphone jack can be connected to display spectrum, voice recorder, transmitter, wireless devices, etc. (not included), also can be plugged into the dual channel line for direct recording, can detect abnormal noises from heating ducts, fire ducts, water pipes, underfloor heating ducts, automobile, home plumbing, and more. 4. WITH CHARGING INTERFACE: Through wall door microphone with charging interface, the built in battery can be repeatedly, fully once available 5 to m7 hours, machine jack and upward switch knob, easy to use and adjust. 5. EASY TO OPERATE: firmly against doors, window and wall and adjust the sound with the knob hear a clear sound, to emit sound from wooden wall, bricks, window and doors, effective noise filtering and faster sound detection. Item Type: Through Wall Microphone Amplifier Amplifier Battery: Lithium Polymer Battery (Ship with Inbuilt Battery) Capacity: 100 mAh Sound Input: 32ohm Headphones Probe Sensitivity: -60dB Maximum Voice Frequency Amplification: 13000X Working Time: 5-7 Hours Probe Power Consumption Current: 12mA Use: Can Detect Heating Pipes, Fire Pipes, Water Pipes, Floor Heating Pipes, Automobile Abnormal Noise, Household Pipes How to Use:Remove the product and use it Note: due to different production batches, the product appearance and printed words be different, which not affect the use. Color:Black Material:plastic Package Contents: 1 * Water Leakage Detector Kit(without words) 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.