The PH-80 has proven to be the MOST reliable pH meter in its price range. It has become a favorite in such applications as hydroponics & gardening, pools & spas, aquariums & reef tanks, water ionizers, drinking water and more. The HM Digital PH-80 Handheld pH / Temp Meter is an economically priced, reliable pH meter. The PH-80 HydroTester is ideal for testing applications such as hydroponics and gardening, pools and spas, aquariums and reef tanks, drinking water, water ionizers Measures pH and temperature Simultaneously displays both pH and temperature Large LCD screen Water resistant Sleek, lightweight design Automatic temperature compensation Auto-off function, data-hold function and low-battery indicator Long battery life: approximately 2 years Includes a cap, batteries, storage solution and pH7.0 buffer Factory calibrated: The PH-80 meter is calibrated at the factory to pH 7.0 and can be quickly and easily recalibrated to pH 4.0, 7.0 or 10.0 using the meter's simple digital one-touch process.