OLFA-Protect a larger work surface. Includes two 23x35 inch mats and two mat clips to tightly hold the mats together for continuous cutting and numerical measurement. Self-Healing Rotary Mats extend the life of rotary blades and protect cutting surface. 1.5mm thick, double-sided, triple-layer mats with dark green base color and yellow grid lines on one side and solid green on the reverse. Store mats flat, do not roll. Keep away from extreme heat and cold.