This Chessex Battlemat is useful for many role playing games (RPG) and miniature games available today. Mats are made from expanded vinyl and work well with wet erase markers. Measures 26 (66cm) x 23 1/2 (60cm) Mat is reversible with 1 squares (22 x 25 squares) on one side and 1 hexes on the other side. Please note: Never use dry erase, permanent, or grease-pencil markers. The vinyl is too porous for the lines created from them to be able to be removed. Use water-soluble markers/pens. If you have any doubt of the suitability of any particular marker, draw a small line on the border, let sit for a while, and see how well it can be removed. Better to have a small permanent blemish on the edge of the mat than a permanent map drawn on the entirety of the mat.