Reliable and durable Inner Tube for 20x4 Fat Bicycles. Compatible with fat tires from 20 x 3.5 up to 26 x 4. Made with a high-quality Butyl Rubber Compound it features better sealing performance, ozone resistance, anti-aging quality, and electrical insulation proprieties. Valve type is A/V32mm Schrader Valve. Installation is quick and easy; follow guidelines outside of the box. The Tube, designed for enhanced performance, has excellent capabilities in high and low temperatures, allowing it to be used on mountains, roads, and snow. Acting as your first layer of shock absorption, this tube can be PSI adjusted for improved traction on sand/snow or more responsiveness over more hard consistent surfaces. Please do not hesitate to reach out with questions or comments!! Customer satisfaction is our priority.