GLB Pool and Spa Products 71265 1-3/4-Pound Chlorine Stabilizer Specially designed to reduce chlorine loss from sunlight exposure Maximizes chlorine efficiency A properly stabilized pool will significantly reduce rapid dissipation and loss of chlorine caused by chemical reaction in intense sunlight Chlorine stabilizer acts as a "shield" against such loss Measures 9.3-inches in length by 3-inches in width by 2.7-inches in height