The Bluelab pH Probe is a replacement pH probe suitable for use with Bluelab products that test the pH value of a solution.
Unfortunately, pH Probes do not last forever as they age through normal use and will eventually fail.
With good care and use (keeping the probe tip wet and cleaning once a month), you will extend its life.
The Bluelab pH Probe has a Double Junction Reference which provides a longer life than many other pH probes and is a gel-filled non-refillable probe, so apart from cleaning is maintenance free.
Replace only the pH probe, not the whole meter.