This is a whiteboard marker holder that you can use to draw multiple straight lines or a music staff. It can hold up to 5 markers. Inside it has little nubs that stick out, and will fit into the hole on the bottom of expo whiteboard markers. This way the markers are held still and will not move around. The distance between the centers of each marker will be 1 inch.
Both stls and ipts are attached. all measurements are in inches.