nerf short cat lynx cheek rest modification

Use two M3*10 countersunk screws.

The cheek rest area has been extended compared to the initial version, which should adapt to the non-extended rear stock; The cheek rest height has been lowered, the initial version was higher than the rail, which looked awkward; Fixed screw holes have been added, so it won't move around easily, some small letters have been added to fill the blank space, they are just random, the 0.2mm layer height is not clear, you can try a lower layer height.