Available in 30mm, 35mm, 40mm, and 45mm sizes. Cutters are measured using the longest inside of the cutter. Using Clay Cutters: Cut clay on a smooth tile, such as ceramic or glass. If clay sticks to the cutter, try a release agent or use plastic wrap. Clean cutters using a microfiber cloth or hand wash using warm water. Dry immediately. Store in a safe place. Expect some sanding to your final clay piece once it is baked. Cutter material may vary in color, depending on what's on hand. All clay cutters are made from PLA filament. PLA filament is a biological material, extracted and purified from corn grain, odorless, and harmless to the environment and humans. Stock up on Polymer Clay here: https://www.etsy.com/shop/OliveTheStuff?ref=seller-platform-mcnav&section_id=37342058 Follow me on Social Media @OlivetheStuff