The recess can be open to the top, with the integral blade subassembly being lowered into the recess, or the recess can open to the bottom, with the integral blade subassembly being raised into the recess.

• 凹穴开口向上时，整体的刀片组就下放入凹穴；凹穴开口向下时，整体的刀片组就往上塞入凹穴。