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 measurement results in the range of 12, 36, 55, 110 and 250 V 3 mm wide flat tip HOW TO USE: To get a reliable reading, turn on the power and squeeze the tip of the meter with your fingers. Touch the tip of the meter to the power plug you want to check.