Jandy Pro Series Levolor With Sensor 50′ And 1″ Valve 110/220V is ideal for pool and spa systems with water features where evaporation and splash out is common. It can be placed wherever a constant level of water can be measured, such as skimmers or static pipes. This sensor also features a time-out sequence that guarantees against overfilling and hiding leaks, as well as a waterproof enclosure suitable for mechanical room environment. No extra in-deck canisters or under-deck pressurized fill lines and no moving parts.