Seedburo offers portable waterproof pH testers with three-point (USA or NIST) push-button calibration with buffer recognition. Three models to choose from: PH10 with ±0.1 pH accuracy, PH20 with ±0.01 pH accuracy or PH30 with ±0.01 pH accuracy and temperature display. Each tester has a replaceable double-junction, polymer sensor, auto temperature compensation and self-diagnostic messages. Also available, a waterproof calibration kit (less meter), which contains all the material you need to calibrate in the field. Contains two single-use pouches of 4.01, 7.00 and 10.00 pH, rinse solution, one sample jar, instruction manual and sturdy carrying case.