THIS WORK MAT IS MADE OF FOOD GRADE SILICONE OVER REINFORCED FIBERGLASS AND WILL FIT ALL STANDARD QUARTER SIZE SHEET PANS. THE MATS WILL WITHSTAND TEMPERATURES OF UP TO 500°F/260°C. THE SILICONE IS NATURALLY NON-STICK, SO NO GREASE, FATS OR OILS ARE NEEDED' SAFE FOR USE IN THE OVEN, MICROWAVE OR FREEZER.