Custom Accessories 41119 Compensating Battery Hydrometer, 1 Pack

Item well packaged in retail blister pack surrounded by crumpled brown paper inside a heavy cardboard box. I removed the bulb end to get the float (enclosed in foam) out, because I couldn't remove the other end. I then reinserted the float and reassembled the roughly foot long device. I tested 2 known to be good batteries and 1 known to be bad and the hydrometer functioned properly. Temperature compensation thermometer worked and higher temp of just the used battery was indicated. After testing I rinsed the unit inside and out with fresh water, then disassembled and dried and reassembled with the float inverted and wrapped in original foam. The device is made of glass and rubber. The glass is fragile. You can't just throw this, or any hydrometer, in a tool box. The rubber, like any rubber, will break down if left exposed to battery acid. The unit needs to be rinsed after use.