... ~ 9999ppm Pen type digital tds meter, all in one, tds electrode is included, FEATURES* 0 to 9999 ppm* LCD indicates ... off without operation in 5 mins* Easy to change the tds electrode*Microcomputer circuit, intelligent function, high accuracy* Temperature measurement, °cor ... battery (LR44) x 4 PCs* Pen type digital tds meter, all in one, tds electrode is included, easy for general purpose application ...