Whiteboard Compass
Use this to draw perfect circles on a whiteboard (or chalkboard) with a dry erase marker (or chalk).
Can draw up to a 9" radius at 1" intervals (also 24 cm at 1 cm intervals).
The body of the compass prints in 2 pieces and snaps together with an opposing dovetail joint. The slider must be attached before snapping the pieces together.
You will need a suction cup with a mounting base that fits through the 0.5" hole.