This is a PP100 Universal Pool Plus pH Probe, single-junction, with a 10 foot cable. These Sensorex universal probes have BNC connections and are compatible with Strantrol, Polaris, Chemtrol, and Rola-Chem controllers.
The Pool Plus sensors feature a high molarity reference design for stability, reliability, and maximum service life in demanding pool and spa applications. The Pool Plus probes also feature a Salt Crystal Reference which is a visual indicator so you will know when to replace the sensor.
You no longer have to guess if your sensors are working. You will know when it is time to replace them.