Houcheng Fixed Gear / Road Airless Bike Tire, Solid (Tubeless) Flat Proof Bicycle Tire - 700 X 23c Weight: 600g Size: 700 x 23C Sidewall and tread are all solid color. Specially high-strength nylon, thicker, more wearable, more anti-stab. Each Flat Proof Bicycle Tire has a Flat Proof Inner Tube and a Rubber Tire together to make the best possible tire for your heavy duty and rugged needs.