Easy to use and clean for the silicone material, high temperature, corrosion, hardness soft toughness appropriate. Assorted gem shapes with hole, Inside the is smooth to give you a shiny finish and therefore no need for polishing. Can be used as Resin, Cabochon, Polymer Clay,Soap and more Perfect tools for your DIY craft projects make pendant, earring, necklace, bracelet, and other jewelry making It's perfect for using it with resin, you can add beads, rhinestones, sequins, colors, dried flower, pictures or anything you like. Specification: Material: Silicone Color: Clear Total Size: Approx. 89 x 78 x 8 mm, Hole Size: Approx. 1mm Drop Size: Approx. 28 x 20mm; 12 x 9mm; Heart: Approx. 12 x 11mm, 22x20mm, 26x19mm, 22x22mm; Oval: Approx. 29 x 21mm; Package Includes: 7 Cavity Silicone