Sigel Marker Chalk 150, Chisel Tip 5-15 mm, YellowSigel Marker Chalk 150 easy to wipe off for glass and all smooth surfaces similar to glass Sigel GL173 chisel tip 5 15 mm highly opaque Fluo Yellow Striking effects and clearly legible notes are guaranteed with this chalk marker 150. The colour covers surfaces extremely well even dark ones and is ideal for writing on glass and all other smooth surfaces similar to glass. The chalk can be wiped off cleanly using either a damp or dry cloth: we recommend