Waterproof pH Pen
Easy to use, rugged pH pen with 2 to 12pH range
pH range: 2 to 12pH
LCD displays pH eadings
Easy to calibrate single CAL key with automatic pH buffer recognition (4, 7, and 10pH)
Choice of 3 point calibration for better accuracy
Data hold freezes reading on display
Low battery indicator, Auto power off
Complete with built in electrode, sensor cap, inner pH electrode protection cap, and 4 LR44 button batteries
datasheet: http://www.extech.com/instruments/resources/datasheets/PH50_60.pdf