Detailed Selling Lead Description Feature: 1) Three-position switch with selection of visible alarm or audible and visible alarm, and power supply controlling is convenient, smart and fast 2) Optional earpiece output for audible alarm, available in noisy and quiet environment 3) Tone identification: making use of the character of ATD, the machine only makes audio- frequency change when you detect small metal articles but makes audio-frequency change and tone change simultaneously when detecting big articles 4) Reset function: put the key gently to make the machine to the work-waiting state, especially when false alarm appears or the temperature of detecting environment changes 5) Low Voltage indicators: continuous alarm, green light stop flashing and red light flash Outer packing: carton