Trans Instruments Koi Medic Salinity MeterKoi salinity meter is very accurate, and easy to use. To use this unit, simply turn it on, dip it into the pond, and the LCD screen will display the salt content. With an auto shutoff, this unit also includes a protective case. The Koi Medic Salinity Meter has a drop shock of 6', 150 hour of battery life, is water resistant, has a low battery warning, 0. 00 1. 00% range 0. 01 resolution, and includes four 1. 5v button cell batteries.