Measures 2-1/2" side to side. Made of specially-coated plastic, these reusable heart-shaped resin molds are great for resin, polymer clay, and casting powders like Jesmonite, EcoCast, ResinCrete, Eco Resin, etc. Pour thin or thick to make jewelry, ornaments, and embellishments. To de-mold, first loosen sides, then flip upside down and tap on table or counter until casting drops out. Pushing from back can dent mold. If stuck, place in freezer for a few minutes then try again. These are the last we have in this type of material, these have soft lines across the bottom of the mold, which will not affect face-up castings.