Snore Stopper Nose Vents EASY TO USE - These Liquid Chalk Glass Markers are really easy to use for both kids and adults, they clean up easy with a dump cloth of paper towel. PRIMING - These Chalk Markers take about less than a minute to Prime when new, just push in the tip over and over till you start seeing chalk ink come down the tip. REVERSIBLE TIP - If you feel like one side of the tip is not working well, pull it out and use the other end of the tip.BIG 6mm Tip - Each Marker has a 6mm tip that is not too small or too big to make beautiful creations with ease BEST SURFACES To Use these markers on- Non Porous Surfaces. Like white boards, LED Writing Boards, Bistro Boards, Menu Boards, Chalk board Stickers, Glass, Metal, Kid Friendly - If somehow the Liquid Chalk gets on clothes or hands it easily washes off BRIGHT NEON MARKERS - These Liquid Chalk Markers are bright especially on dark backgrounds they contrast really well. Perfect for LED boards