Star A211 pH BT Meter pH Range -2 to 20 Waterproof IP57 Automatic Temperature Compensation Yes Displayed Temperature Range 0 Degrees to 120 Degrees Operating Temp Range (F) 0 Degrees to 120 Degrees Display High Resolution Mono-chromatic Auto Power Off Yes Calibration 5 pt Power Source AC or (4) AA Battery Includes Star A211 pH BT Meter with Electrode Stand Manufacturers Warranty Length 36 mo Testing Parameter pH