single function valve cartridge controls the temperature at full output flow. Monitors water pressure to balance temperature. All Delta® tub and shower faucets are engineered to keep the water temperature within a safe +/- 3.6 deg F (+/- 1.7 deg C). This technology makes sure your family doesn't experience a sudden and possibly unsafe change in water temperature as a result of running water elsewhere, such as using a dishwasher, flushing a toilet or running a washing machine. The valve cartridge features an adjustable handle limit stop that, when properly set, helps ensure the handle cannot be turned to a position that is too hot for comfort. The handle limit stop's integrated design allows easy adjustment via pull and turn. Easily replaced seals make maintenance a snap. Comes with all Delta® pressure balance tub and shower faucets. Requires inlet water temperature be set correctly. May require seasonal adjustments.