Oakton Waterproof EcoTestr pH2 is a convenient pH meter that doesnt let dirt or moisture keep it from delivering accurate readings. It features a clear LCD display, a waterproof, dustproof housing, automatic shutoff, and it floats! Measures pH from 0.0 - 14.0 with a resolution of 0.01 and ±0.1 accuracy range. It automatically compensates for variations in temperature, and remembers up to three calibration points. Includes four 1.5V button cell batteries and single-junction electrode.