Keep your swimming pool water safe and clean by eliminating dangerous contaminates. Blue Waves premium chlorinating sticks are manufactured using only the highest quality EPA-approved chlorine and feature 90 percent available chlorine! These extra large 8 oz. sticks are very slow-dissolving so they require less maintenance. Each stick measures approximately 2 1/4in x 2in in diameter. Use this in your floater, automatic chlorinator or skimmer basket.