These were designed to be used with inexpensive drawer or cabinet knobs/handles. There are two types, rotating and non rotating. The non rotating ones (x2) get a screw epoxied in from the back then mounted to the wall. Then a knob is threaded on for a clean screw free finish. The rotating types are used to hold the board in from the top. Drill a hole in the knob offset so that it will swivel out of the way of the other two screw holes when turned. Then insert 2 screws through the front into the wall.
Use two non-rotating type to support the board from the bottom and 1 rotating type to lock the board in from above.
I designed these because I wanted something with a nice finish and I found a pack of 12 of these knobs for $2.50 at my local hardware store. They are spaced away from the wall enough to work with both camber and rocker boards as shown in the images above.