Simple sanding tool for 230x30 piece of sandpaper

I wanted a sanding tool that can be used both on the table for smaller things and in the workshop for a bit larger tasks, found almost nothing for that size despite the huge number of different models.
Two-sided designs by Perinski seems to be most functional, so I've taken one as the base.
Sandpapers I use come in 230x280 sheets, so I've designed about 10cm two-sided tool that suits the standard size.
30mm width seems to be most comfortable to hold between large and middle fingers.

The only thing that needed additionally is the M4x20 screw. Knob is designed for round-head socket screw, but you can use the tool without knob.
There are no thread in the wedge hole, you can tap it right with the scew or with tapping tool.