Plumb Pak Bubble-Stream Aerator 1.5 Gpm 30 % Water Savings 15/16 " Chrome Lead Free 27 " X 55/64 " C This product meets California AB1953 and Vermont S152 requirements Interior Thread Size: 55/64 in. - 27 in. Exterior Thread Size: 15/16 in. Use with inside thread faucets Recyclable clamshell packaging