HI 99141 is a waterproof, portable pH/ temperature meter supplied with a flat tip probe specifically designed for boiler and cooling tower applications. The HI 72911D pre-amplified double junction pH probe features a recessed flat tip that is easy to clean and prevents solids in solutions from collecting on the sensor. The titanium body of the HI 72911D functions as a potential matching pin for increased stability of readings and extended sensor life. Order Information: HI 99141 is supplied with HI 72911D pH/ temperature probe, HI 70004 pH 4.01 buffer solution sachet, HI 70007 pH 7.01 buffer solution sachet, HI 700661 electrode cleaning solution sachets ( 2) , batteries, instructions and hard carrying case.