The Fluke 1555 insulation tester is a handheld device used to measure the insulation resistance of electrical equipment. It is designed for use in a variety of applications, including testing motors, generators, transformers, and cables. The Fluke 1555 is a rugged and reliable tester that is built to withstand the demands of field use. It features a large, easy-to-read display, and a simple, user-friendly interface. The Fluke 1555 is a valuable tool for any electrician or maintenance technician.