This listing is for a high quality (made in Taiwan) Lower Knife

 #412749 

Fits Singer Overlocker/Serger Machine Models: 14U234,

 14U285, 14U286, 14U34, 14U34B, 14U344, 14U354, 14U44,

 14U44B, 14U344B, 14U354B, 14U444, 14U454, 14U454B, 14U46,

 14U46B, 14U64A, 14U65B, 14U85B & PRO4D

Also for Pfaff 756;  

Elna T3, T33, T34, T34D, etc. etc.