Specifications: 1) Power: one 9V alkaline battery 2) Operating frequency: 50kHz ±10% (sine wave) sensitivity: ≥5cm 3) Indication: audio alert and led (red) alert, audio tone changes as the metal size changes 4) Silent operation: connects the earphones to the detector for silent operation 5) Blink: when the unit is working properly, the blink indicator flashes 6) Headphone jack: 1/8" 7) Low sensitivity: to lower the sensitivity, at this time the sensitivity is >2cm 8) Low battery indication 9) N.W.: 350g 10) Unit dimensions: 440 x 67 x 36mm 11) G/B dimensions: 430 x 82 x 51mm Packing: Gift box