The Swimline HydroTools 87502 automatic chlorinator will reduce the time spent maintaining proper chlorine levels by supplying the exact amount needed. The durable, corrosion-proof canister holds up to 9 lbs. of chlorine tablets, equaling about 8 to 9 weeks sanitizing. A dial control valve allows for easy regulation of the amount of sanitizer entering your pool. This automatic chlorinator installs easily to new or existing pool filter systems and sanitizes pools up to 40,000 gallons.