The Bluelab pH Probe is a replacement pH probe (electrode) that is suitable for use with Bluelab products that test the pH value of a solution.
Unfortunately, the pH Probes do not last forever, as they get older through normal use and ultimately give no reliable values. With proper care and use (keeping the probe tip wet and cleaning it once a month) you will extend your life.
The Bluelab pH Probe has a double cross reference, which gives a longer lifespan than many other pH probes and is a gel filling that cannot be refilled. Cleaning is maintenance free.