[Water Quality Detector Set] Includes 1 piece pH tester and 1 piece 3-in-1 TDS tester (measures TDS, EC, and temperature) [Measure Range] TDS: 09999 ppm; EC: 09999 S/cm; pH: 0.0014.00 pH; Temperature: 0.180.0C; 32.0176.0F [Backlight] Both pH meter and TDS/EC meter feature a backlight function [pH Calibration Powder] The pH meter comes with 2 sets of pH calibration powder. Each package must be mixed with 250 ml of purified or distilled water [Power Supply] TDS/EC pen powered by 1 CR2032 battery. The pH meter is powered by 2 LR44 batteries Color: Yellow & White Material: ABS Package Contents: 1 x pH Tester 1 x TDS Tester 6 x pH Calibration Powder Only the above package content is included; other products are not included Note: Light reflection and different displays may cause slight color variations between the image and the actual item. Measurement error allowance is +/- 13 cm