Hayward CAX-20255 1/4-Inch Check Valve Replacement for Hayward Cat 1000 Commercial Automated Controller Monitors 1/4-inch check valve Fits hayward cat 1000 automated controller monitor models cat-1000-co2, cat-1000-co2-ul, cat-1000-orp, cat-1000-orp-ul, cat-1000-ph Also fits hayward cat 1000 automated controller monitor models cat-1000-ph-ul, cat-1000-ptc, cat-1000-ptc-ul, cat-1000orpptc, cat1000orpptcul Weighs 0.2 pounds