The IDEAL® 61-637 is Cat IV 600 VAC, UL Listed, single range non-contact Voltage Tester that automatically detects and indicates the presence of voltage within range of range of 24 to 600 VAC . The tester provides non-contact detection of voltage through an antenna enclosed in plastic at the tip of the tester which senses the presence of the electromagnetic field present around live conductors. The tip is illuminated by a green LED when powered on and switches to a red flashing LED, and audible beep that increase in frequency as the voltage level increases. The tester is powered by two 1.5 V AAA batteries and features an in tip LED flash light, an audible disable function, a lanyard tie-off point, an auto power off function and a low battery indication.