Made of Premium soft Silicone: Agency certified non-toxic materials, Eco-friendly and safe for the human skin.It is waterproof, Anti-sweat, rainproof. Two Selected Sizes Large size: fits for 6.7"-8.1" wrist Small size, fits for 5.5"-6.7" wrist. You can always find the most suitable size here. Classic and Simplicity:transform your new Charge 2 with our accessories wristbands to create a quintessentially classic look, which conforms to ergonomics, Great wearing experience. Easy to Replace: Simple to install and take off, no tool required. Black bands fit your daily style& any occasion. After-sale Service : For any problems, please contact us, we will give you a perfect solution within 24 hours .