Whiteboard Wall Mount

I bought a wooden framed Whiteboard that I wanted to wall mount in my little office but the 2 hook eyes supplied looked pathetic especially when I have small kids around. I designed this mount to hook over the frame with a screw hole.
I printed 4 of these to mount to the wall and is fairly sturdy and hopefully safe from my kids!

My whiteboard frame is 17mm wide with a 4mm internal depth and 15mm outer depth. I made each 20mm long. I'm using small wood screws straight into plasterboard with about 3mm max diameter.

Both sketchup file(2017) and STL provided.