Apera Instruments EC60 Premium Waterproof Conductivity Pocket Tester, &plusmn;1% F.S Accuracy, Easy Switch of EC/TDS/Salinity, Replaceable BPB Sensor APERA's unique Replaceable BPB (Brush-resistant Platinum Black) probe ensures high accuracy and consistency in a wide-range conductivity measurement EASY Auto Calibration with auto buffer recognition; Auto Temp. Compensation (ATC) ensures accuracy in variant temperatures (0-50.0C) LARGE CLEAR LCD with 3 backlit color (indicating 3 different modes), DUAL Display of temp./EC, and indications of completed calibrations and stable readings EASY Switch from EC to TDS/Salinity with customizable TDS factor (0.40-1.00) Complete kit with READY-TO-USE calibration solutions, calibration bottles, AAA batteries, and a lanyard all in a premium portable carrying case