Wall mount pen/flashlight/tool clamp

A wall mounted clamp for a single pen. I'm using it for permanent markers which I want to have available at different spots without having to hunt for one. These clamps help keeping the pens at a fixed location.
Attached to cupboard or walls with a small strip of super sticky tape. Pens can be dropped into the clamp from above, or pushed into from the front. Beveled at top for smoother pen insertion action.
While the object is a rather simple one, it's usefulness outweighs the manufacturing and mounting efforts.
Easy print, low material requirements. First person who noticed them already asked for a bunch of them.
OpenSCAD file and Customizer, as pen diameters differ. The uploaded STL fits pens with a diameter of 12.8mm. It also happens to fit my dual-AAA cell flashlights perfectly. For other pen diameters, customize or rescale it according your needs.