Multi-function insulation tester with backlit dual display, double molded plastic housing and lock function for hands-free operation. This insulation tester is capable of measuring 250V, 500V or 1000V test voltages and insulation resistance up to 2000M?. The R5600 features a large, easy-to-read backlit dual display, durable double molded plastic housing and lock function with hanging strap for handfree operation in the field.