... desired value* Water proof * Auto power off without operation in 5 mins* Easy to change the tds electrode*Microcomputer ... V battery (LR44) x 4 PCs* Pen type digital tds meter, all in one, tds electrode is included, easy for general purpose ... , laboratory, quality control, school & colleges, swimming pools, water conditionsSPECIFICATIONSDisplayLCD, size : 20 mm x 27 mm. ConsumptionMeasurement Rangetds0 ...