part 49123 Backup Ring, Valve Retainer Cat Pumps code 49123 Details Cat Pumps number49123 DescriptionBackup Ring, Valve Retainer Qty per pump1 Also comes in 31708 Kit, O-Ring (Includes: 414, 415, 424, 428-430 Fits these pumps Cat Pumps Plunger pumps 4 66DX30G1I66DX35G1I66DX40G1I66DX50G1I