Koi Medic Salinity Meter is a very accurate, easy to use salinity meter. Simply turn on and dip into pond, LCD display will display salt content. Includes protective case. Has an auto shutoff, drop shock 6', 150 hour battery life, water resistant, low battery warning, 0.00 - 1.00% range 0.01 resolution. Includes four 1.5v button cell batteries.