The VIBRA-PROBE 460 is a water-proof, pulse induction, pin-pointing metal detector. By simply holding the tip pointing upward for 1/2 second, an internal switch provides automatic turn-on. You will feel two pulses of vibration that verifies the probe is working properly. An internal clock automatically starts and will turn off the probe in one minute unless you have detected a target, in which case the one minute clock will start again. When the VIBRA-PROBE 460 does turn off, it informs you with two distinct long pulses of vibration. The VIBRA-PROBE 460 is powered by one standard nine-volt battery