Base of posts measure 2 1/8" diameter and will fit into the bottom of most standard size cupcake pans. To use cupcakes posts, place them into the bottom of cupcake pan and push liners onto posts. Push treats onto the posts and fill with batter. Bake, remove the posts, and enjoy cupcakes with hidden surprises in the center! Bake cupcakes with fruit, candy, or even cream cheese in the center. Cupcake posts are made of metal.