Dry erase markers are the recommended writing implement to use in the device, however other implements (i.e. pencils, pens and markers) will work just fine. To insert an implement, simply drop it into the holder and tighten the thumb screw. The 3D printed / PVC holder is designed to catch a standard dry erase marker so that the tip is about 1/4-inch above the writing surface.
Other writing implements can be used as long as they are secured by the thumbscrew with about 1/4-inch from the tip to the writing surface.