SATISFACTION GUARANTEED : Your enquiry is our first priority. If for some reasons, you are not 100% satisfied with your purchase, BWSHLF will send you a full refund. Any question, please send us e-mail, 24-hour online just for you. QUALITY TESTED : All tubes are molded and cured to ensure uniform roundness and better reliability. Every tube passes a strict 100% quality control inspection. Fits all 20X4.0 inch fat tires. A/V Scharder Valve 48mm. 2 pack. EASIER INSTALLATION : You will get 2 inner tires and 2 tire levers at one buy. With the assistance of tire levers, even a green hand could easily take the tube out from the tire when changing the tube. MORE STABLE : With an extra locking ring, our tubes fix the valve into the rim more stable compared to the traditional Schrader Valves. Such a detailed design helps you avoid replacing the whole tire due to the damage of Schrader Valve. BETTER ENDURANCE : The premium butyl rubber adds good air tightness and better durability to the tube. The rubber is thicker compared with the common tubes, which has outstanding performance in puncture resistance and endurance. Thus saving your money and energy from changing the tubes frequently.