1. Material: silicone2. The large size is suitable for wrist circumference: 7.1-9.1 inches, and the small size is suitable for wrist circumference: 5.5-7.8 inches.3. Technology: This product is made of silicone material, which is waterproof, sweat-proof, comfortable and soft.4. The watch strap adopts a thickened design, which is comfortable to wear and easy to use.5. The material is harmless to human skin and non-allergenic.6. The strap length is easy to adjust to fit your wrist.Note: There is only the watch strap in the package, nothing else