NUDGE Liquid Chalk Markers - 10, 6 mm Marker Pens - Wet Erase (Wet Wipe) - Reversible Tip (Chisel & Round Tip) Lifetime Quality Guarantee: Call us/Email us on issues and you'll be happy - Guaranteed Reversible Tip & 2 Extra Tips Included: Each tip has a Chisel and Round shaped end Supported Surfaces: Non-Porous Chalkboards, Whiteboards, Glass, Metals, Plastics, Mirrors, Ceramics, Displays, Windows Warning: Not recommended for Chalk Painted Surfaces Digital Art Library & Lifetime Membership Account: Downloadable from our Website (i.e. no physical goods shipped)