Check Ball, Compatible with Grainger Part Number 3FPR2, 3FPR3, 4RN38, 6CCN7, 6CCP6, 6CCR1, 6CCR4, Compatible with Manufacturer Model Number 666251-EEB-C, 66625C-8EB-C, PD20A-AAP-AAA-B, PD20A-ACP-AAA-B, PD20A-ACS-HAA, PD20A-ASP-AAA-G, PD20A-ASS-AAA-B, PD20P-FPS-PAA, Material Santoprene, Product Type Check Ball, Compatible with Pump Type Diaphragm Pump, Compatible with Series Expert-Series, Compatible with Brand ARO