The MILWAUKEE GFCI Receptacle Tester and Voltage Detector is built for the pro electrician. The Voltage Detector can be used for residential, commercial and industrial applications. With the highest safety rating in the industry, CAT IV 1000V, the Voltage Detector can detect a wide 50 to 1000V AC range. A blinking red light and loud beeper indicate the presence of voltage. The Detector includes two (2) AAA batteries and is covered by 1-year warranty. The Milwaukee GFCI Receptable Tester is designed to reduce the risk of electrical shock generated from outlets. The over molded grip provides durability and comfort for all applications. Additionally, the visual indicator light turns on indicating the activation of the GFCI test, if functionally correct. LED visual indicators help determine the wiring conditions of an electrical outlet. Wiring conditions indicated: hot & ground reversed, hot & neutral reversed, open hot, open neutral, open ground, and correct wiring. The GFCI Receptacle Tester is covered under a 2-year warranty.