The family of 12 testers offers convenient portable solutions for pH ORP conductivity TDS salinity and temperature. The Pocket Pro+ testers take the value a step further with replaceable sensors powerful backlight and multi-parameter tester options. Confidence in Results Easy calibration steps and built-in diagnostics for pH testers take the guesswork out of calibrating the sensor to keep it in optimum condition. Save Time and Money Easy-to-replace AAA batteries and a convenient sample cup make maintenance and measurements simple. Ease of Use The large LCD screen is easy to read; backlighting is included on Pocket Pro+ models allowing measurement in almost any lighting environment.