Features:Premium steel makes it strong and sturdy, and has a long service life.Excellent workmanship, smooth and without burrs.Replacement for the old or the bad,easy to install and use.Erosion resistant, high strength and durability.A good sewing machine accessories to make your work more efficient.Specification:Item Type: Serger Machine KnifeMaterial:Metal Upper Knife Code:412585Lower Knife Code:550449 Fitment:Fit for BABYLOCK SERGER MODELS-BL202,BL302,BL400Fit for CONSEW:14TU854Fit for ELNA SERGER MODELS:T-3,T-33,T-34,T-34D Fit for SERGE-MATE SERGER MODELS:300,430,SW432,4350D,5030,5949LUpper Knife Size(L x W):4 x 0.8cm / 1.57 x 0.31inLower Knife Size(L x W):2.5 x 0.8cm / 0.98 x 0.31inPackage List:1 x Upper Knife 4125851 x Lower Knife550449 .