QualityParts From Oregon That you can depend on. Requires 2 blade for 42" cut: Fits 100 series tractor; 100 Series Blades formed with double bevel technology for extended cutting edge and reduced blade noise; Major brand replacement: John Deere; Replace OEM No. GX20249, GX20433, GY20567; ; Oregon Equipment Parts 191-139 BLADE,JOHN DEERE 21-3/8 IN