Security Metal Detectors, GoerTek Hand Held Adjustable Sensitivity Super Wand Scanner with 16 LED Lights Variation Show the Strength of Metals&rsquo; Signal one 9V Battery Included Range -15 ~ 6 16pcs LED indicators: Detecting the strength of metal's signal easily -- Indicator lights gradually change from green (weak signal) to red (strength signal)) when detecting the different sizes of metal objects. Adjustable sensitivity: With Low sensitivity switch, easily switch the sensitivity, realizing the detection of small goods from bulky goods. Alarm indication: Blinking green LED means power on, Blinking red LED means target has been detected, Continuing yellow LED (side) means low voltage directive. Two alternative alert ways: Audio and Vibration; Portable hand held metal detector, detecting temperature range is -15 ~ 65. Powered by one non-rechargeable 9V battery (included),with an external charging port, you also can fully charge it with a rechargeable 9V battery (not included).