Diaphragm Pump Repair Kit, Check Ball Material Polyurethane, Compatible with Grainger Part Number 2CAP4, 5U668, Compatible with Manufacturer Model Number 666053-388, 666057-488, 66605J-388, Diaphragm Material Polyurethane, Number of Check Balls 4, Number of Diaphragms 2, Number of O-Rings 11, Number of Seals 11, Valve Type Ball, Product Type Fluid End Repair Kit, Media Intake Pressure (Maximum) 120 psi, Compatible with Pump Type Air Operated Double Diaphragm Pump