... LCD shows both pH & temp.. 2.Compact size, light weight. 3.Auto power off 4.Easy to change the ... in temperature sensor, ATC (auto temperature compensation)Compact size, light weightThree point calibration for pH 4.01, pH 6. ... and pH 9.18Power supply by 1.5 V battery (LR44) x 4 PCsMeter with pH electrode. PT-6021A PH meter ,light ... weight pH meter