Material: Silicone, Stainless Steel 1. Premium silicone mixed with fashion, nobility, durability and elegance 2. Silicone sport strap, precision thin, superior appearance, easy to install and remove 3. The size can be adjusted according to the circumstance of individual wrist. 4. Stainless steel buckle, solid clasp and easy to open and close 5. It is the perfect choice for those who want to make their Apple Watch noble and stylish at a convenient way