WellieSTR Upper Knife Blade fits Pfaff Babylock Elnitalock Riccarlock Simplicity #412585,Serger Upper Knife For Singer serger models: 14CG744, 14CG754, 14SH644, 14SH654, 14U12, 14U13, 14U32, 14U34, 14U44, 14U46, 14U52, 14U53, 14U64, 14U65, 14U85, 14U234, 14U244, 14U285, 14U286, 14U344, 14U354, 14U444, 14U454, 14U544, 14U554, 14U555, 14U557, Babylock: BL202, BL302, BL400, BL450, / Elnitalock: T-3, T-33, T-34, T-34D, Happylock: 1867, /Serge-Mate: 300, 430, SW432, 4350D, 5030, 5040L, Pfaff: 756, 4762, 4772, / Riccarlock: RL613, RL613E, RL624, RL624E, RL634DE, RL724E, 564DE, Simplicity: SL200, SL350, SL370, SL390, SL803, SL804, SL804D, SL843, SL4300, SL4360ED