Efficient and maintenance-free, the Hayward CL200 In-Line Chlorinator is a durable, corrosion-proof automatic swimming pool chlorinator. The Hayward automatic chlorinators use large or small Tri-Chlor slow dissolving tablets or sticks – enough to supply three weeks of chlorine sanitation for a large pools and longer for smaller pools. Ideal for new or existing pools or spas and works automatically with your pump and filter system. Saves time, and reduces manual handling of chemicals. The dial control valve lets you control and adjust the rate of feed. In-line chlorinators go in-line near pool equipment to provide a steady amount of chlorine to sanitize the pool. This Hayward Chlorinator is for use with 1″ or 3″ chlorine tablets or sticks.