Product function: f-999r precision testing instrument, precision accessories with ultra-high information price ratio, automatic noise reduction function, high-definition hearing device, can be used for pipeline side drain / floor heating testing / Geophysical Prospecting water, suitable for pipeline materials, ground, wall, etc. Operation : insert the earplug into the earphone hole, insert the probe, turn the power on / volume knob clockwise, the power indicator light is on, and adjust the gear rotation knob 0123 to select the best effect. Note: the probe must contact the tube surface stably. Please do not drag the probe in parallel to avoid damaging the probe. When using the probe, adjust the audio gear knob 0 '1' 2 '3 to adjust the best effect, and the volume knob to coordinate the adjustment. Normal third gear. Product features: all metal body, fine workmanship, precision high-end professional equipment.Excellent performance, clear sound quality, strong sensitivity, components. The working principle of the instrument isThe sound is gradually amplified by transmitting the sound by the of the physical .It can be heard normally when entering the ear. The larger the leakage point of the detection water pipe, the better the effect. Additional functions: function jack, recording function. Product specification: current consumption: 13-33 Ma battery usage: 9V6f22,not included Working time: 10-23 hours (according to the sound strength) Four section audio selection: 3 (100hz-700hz), 2 (700hz-900hz), 1 (900hz-1100hz), 0 (1100hz-1600hz); Probe sensitivity: - 60dB, maximum audio amplification: 25000 times. color:Gold Material:Metal + Plastic Package Contents: 1 x Host 1 x probe 1 x headset 1 x battery 1 x aluminum alloy case 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.