This professional-grade ORP and pH Sense and Dispense technology was previously only available for commercial pools. Haywards offers an economical approach, with the same level of accuracy, for residential pools. Unlike others on the market, Sense and Dispense uses a proportional feed algorithm that continuously tests the water, sampling pH and sanitizer activity, adjusting chemical feeding on a basis proportional to the demand. Other approaches don't sample te water often enough and release larger doses which is far less effective and can create highs and lows similar to a manual approach. This chemistry kit senses pH and ORP levels and dispenses a self-renewing supply of pure chlorine generated from salt.