This tester is designed to check the life of any 6 Volt or 12 Volt Battery. Each tester is calibrated to ensure accuracy. Perfect for use around the ranch or the house. Its dimensions are 6" long and 1" wide, fits great in a shirt pocket and has a built-in belt clip. Puts a light load on the battery, retractable probe, and also features a small screw driver set that can be used as a secondary probe.