Hayward SP1500UNPAK2 1-1/2-Inch Socket ABS Quick Connect Union Pak Replacement for select Hayward Pumps/Filters and Chlorine Feeders, Set of 2 Quick connect union pack includes 2 each of socket connector, union nut, O-ring Fits Hayward Perflex extended-cycle DE, Pro-series top-mount sand and XStream Filtration series above-ground Full-Flo pool and spa filters Also fits Hayward Power-Flo Matrix above-ground pumps and CL100/CL200 chlorine feeders Made of ABS plastic material It has 1-1/2-inch socket end