Flexible Nonstick Silicone Withstands Temperatures Up To 428deg F Built-in Reinforcements For Optimal Handling Molds Nest Inside Each Other For Easy Storage Round Shape Is Compatible With A Mini Oven Or Microwave Central Vent For Optimal Heat Circulation Perfect For Making Recipes Over A Bain-marie Heart Mold Holds Up To 8 Hearts & Is 9.45" Dia Set Of 1 Heart Mold & One 9.5" Round Cake Pan Mold Red