Cohas Magnetic Backed Marker Tray Set includes 6 Inch Tray with Writing Surface, 1 Tray, Fine Tip White Waterproof Marker Magnetic backed trays are perfect for use with magnetic boards, calendars, whiteboards, and more Featuring a heavy duty magnet, they can be used to hold markers and chalk on steel surfaces Includes white waterproof marker with a fine 1mm tip that makes thin 1/32-inch lines Trays measure 6 inches long and can hold markers up to 3/4 inches in diameter Use liquid chalk markers for writing lettering or illustrations, or use with real chalk