Hand Held Metal Detector (16 LED Lights alarm) 1. Adjustable sensitivity 2. One switch operation 3. LED lights only, red LED and sound alarm 4. One 9V battery required, ( Not including in the price) 5. Operating frequency: 52KHz+/-10%(Sine wave) 6. Audio tone changes as the metal size changes, . It can distiguish the size of metal according to the sound from low to high. At the same time, this model also can locate the place of the metal, it is also the different from other security handheld metal detectors 7. Heavy duty frame, rugged, high-impact case with reinforced coil compartment. ABS materials 8. Detects medium sized pistol from 9; Arge knife from 6, razor blade and box cutter from 3, foil-wrapped drugs and tiny jewelry from 1. Momentary push button temporarily eliminates detection of nearby ambient metal such as metal Dimensions Width 3.25" (8.3 cm) Thickness 1.625" (4.13 cm) Length 16.5" (42 cm) Weight 17.6 oz. (500 g)