Ultra Pure Water ( UPW) is an ideal tester for M© checks. PWT is suited for fields such as printed circuit board washing, laundry, steam cleaning, checking car battery water and all areas where distilled, demineralized or pure water is used. UPW is the first pure water tester to measure in 1/ 1000ths of micro-Siemens ( µ S) and provides fast, on the spot checks for minute traces of contamination in your water. These testers are housed in a durable case that provides excellent protection against harsh industrial environments. Order Information: HI 98309 ( UPW) is supplied with protective cap, batteries and instructions.