Product Description Battery hydrometer professionally gives accurate indications on battery charge status and battery condition. The battery hydrometer tester is designed to test the concentration of the battery acid in non-sealed batteries. Hydrometer tester features - professional quality for highest accuracy - precision graduated specific gravity float - perform tests of the battery in seconds - easy to read, color coded hydrometer - precise readings for status of battery cells - accurately tests battery fluid condition genuine battery product. Product Features Easy Application Solid & Durable Easy to Read How to Use Battery Hydrometer Tester Carefully insert the battery hydrometer into the cell. Press on the bulb that acts as a syringe. You should see fluid filling the hydrometer. Continue to squeeze the bulb until the battery electrolyte solution fills the device to the maximum level. Professional Battery Tester The Professional battery hydrometer is made of standard quality glass rubber material, it has small and light in weight, convenient for you to carry, reduce your burden, safe to use. Compact hand held tester reads specific gravity of battery acid.