CBH34|Champion Battery Hydrometer This economical glass hydrometer features an acid resistant rubber bulb with extra long tip and easy to read float scale. For testing all 6 12 and 24 volt batteries. How It Works After inserting tip of tester in cell draw just enough solution to raise the float. The point at which the scale is level with the top of the solution indicates cell condition. The three colour float indicates the exact cell condition: GOOD (green) FAIR (white) RECHARGE (red) Description Acid resistant rubber bulb Extra long tip Easy to read float scale Pack Size: 1