Specifications: F999M/F999E/F999K Size: 54.5*41*19.5cm Weight: Net weight 6.8kg F999L Size: 40*33*18cm Weight: Net weight 4.5kg F-999L Leak Detector Current: 60mA Magnification: 0-100dB adjustable Voltage: 9V Operating temperature: -100~+50C Working time: >30 hours Instrument box size: 45 x 30 x 15mm Frequency binning: 1-4 gears 200HZ-3000HZ continuously adjustable Weight: Host 900g/Indoor sensor (large) 140g/ Indoor sensor (small) 75g/Handle 160g Product List:1. Detect host 2. Earphone 3. Indoor sensors 4. Indoor sensors 5. Sensor handle 6.Charger 7. Instructions 8. Warranty card 9. Case F-999L Host 1: LCD display 2: The volume knob is also the power switch, turn clockwise to increase the volume, turn counterclockwise to decrease the volume. 3: Frequency selection knob, select the appropriate frequency according to the specific environment. 4: Sensor jack 5: Headphone jack 6: Noise reduction switch: turn it to the B position to turn on the noise reduction function, turn it to the F position to turn off the noise reduction function. 7: The screen displays the sensitivity adjustment knob. Turn it clockwise to increase the sensitivity and turn it counterclockwise to decrease the sensitivity. 8: Charging socket Package includes: F999K/F999L/F999E/F999M (Your choice)