Neilsen Battery Hydrometer - Battery Acid Tester
 
For testing the density of battery electrolyte. With glass tube, PVC bulb, and spout. Clear Scale graduated from 1.10 to 1.30g/ml.
 
Scale divided into 3 colours Green: Fully charged battery Orange: Half charged battery Red: Dead battery.

Battery Hydrometer
For the hot or cold testing of lead acid batteries