The voltage range measured by the tester is 12-250V. The main advantage of the tester is the ability to detect live wires without having to touch the wire. PRODUCT FEATURES: Suitable for home use and electrical professionals. Backlit display shows readings between 12, 36, 55, 110 and 250V 3mm wide flat tip HOW TO USE: Turn on the power and squeeze the tip of the meter with your fingers to get a reliable reading. Touch the meter tip to the power connector you want to test.