The Milwaukee MA73600 is the replacement pH/temperature probe for the pH51 & pH54 Testers (sold separately).
The MA73600 measures pH and easily slides into the tester fitting then screws into the meter body for secure installation.
Milwaukee Instruments handheld testers, portable meters and stationary monitors-controllers are warranted for a period of 2 years and bench meters for 3 years. The PH600 pH Pen and versions of it have a 1 year warranty. Replaceable probes are warranted for a period of 6 months.