The genuine Janome upper serger blade knife fits models: Four-DLB, 7034D, 9002D, HF3434D, HF9102D, HF7933, 8002D, 9002D, 9102D, HF504D, Necchi S34 & Kenmore 385.16622.
NOTE: It is recommended that you replace both blades. Not doing so can damage the new blade.
Serger Replacement Upper Blade for Janome, Necchi & Others