HIGH QUALITY MATERIAL: Made of PVC environment protection material, which is durable, innocuous and safety, wear-resistant, lightweight and with strong anti-pressure ability. The PVC texture provide more ductility than normal rubber liner. PERFECT PROTECTION OF YOUR BIKE INNER TUBE: High toughness and enough elasticity can effectively help to prevent your inner tubes from puncturing by glass, thorns, nails, etc. HOT WELDING TECHNOLOGY: The gas valve hole connected by hot welding process which is more firmly than connected by glue. EASY TO INSTALL: Quick and easy to install, just stretch them over your rims and let them stay in place. (See the attached video). BEST FOR: Great cycling accessory for cyclists. Available in 20 inch and 26 inch, you can choose based on your needs. (Rims for display only)