Rola Chem PH Probe [Digital Analog Ctrl Sys Heavy Duty 8ft] (550135) gentekk 0 kW in line bath heater 0 kW in line bath heater is designed for compatible bath heating applications where a 115 volt heater with a 3 foot cord and plug is needed A heater like this is useful because it provides the core heating function for the supported system while offering a weather tight design that can add confidence in demanding installations Rola Chem PH Probe [Digital Analog Ctrl Sys Heavy Duty 8ft] (550135) is a replacement pH probe for compatible Rola Chem digital and analog chemical control systems This heavy duty 8 ft probe is intended for pool and spa chemical feeder systems where dependable readings are important for water balance