The HM Digital PH-200 ph meter measures pH and Temperature. Auto-ranging three point calibration with digital fine tuning. pH buffer 4 solution is in a sponge embedded in a clear cap. Measurement Range: 0-14 pH with a waterproof housing. Digital automatic calibration (one point), with digital fine tuning. Auto-off, data-hold functions and low-battery indicator. Display: large and easy-to-read LCD screen includes simultaneous temperature reading. Factory calibrated with three-point calibration to 4, 7, and 10 pH. The meter can be recalibrated with digital calibration using the push buttons, no screwdriver needed. Includes a cap, batteries, lanyard and pH 7.0 buffer.