Deka Standard Hydrometer is a float‑type battery tester with a clear glass tube and color‑coded float to quickly read electrolyte specific gravity and battery state of charge. It is large in size for easy handling and has a tip designed to prevent rolling when placed on a flat surface, making it practical in workshops and garages. Ideal for automotive and deep‑cycle batteries, it helps diagnose weak or failing cells so the user can decide whether to recharge, equalize, or replace the battery.