stainless steel, food grade, smooth, not easy to to food debris. 3 1/2-inch round. Easy to use: Just place the filling and sauce between two layers of bread or dough, then cut and seal. Easy to clean: the quick split is more convenient to clean after use. Dishwasher . It is a great to making a and mess-free snack or school kunch for your . Enjoy the fun of , jelly sandwich, hamburger, pie, art.