Its 775/795 motor Removable Grass Cutting Coupler with Blades Set. We generally use normal wood cutting blade in grass cutting but efficiency of that is too low. Here we invet a new coupler with HSS blades to cut grass very easily with m10 arbor compatible one. This Coupler is compatibe with both O shaft and D shaft Motor. Its removable set so you can use the motor in other application also.
You can use this m10 arbor set also to other application. 
Package Include -
1 x Coupler ( Diameter - 50 mm)
10 X Cutting Blades set
4 x nut bolt and washer set
1 x M10 arbor full set
Motor Not Include In This Set