Features: LED detects the presence of AC current. Locate breaks in power cables and wires. Non contact testing for complete safety. Convenient pen size with a pocket clip. 2 x 1.5V AAA Alkaline Batteries included. Specification: Voltage Detection: 50V-1,000V AC. Frequency: 50-500Hz. Measurement: CAT II, 1000V. Category: CAT III, 600V. Warning: Always test on a known live circuit before use. This detector is not designed to carry out contact tests on live supplies. Any other form of test should be carried out by a qualified electrician.