The SEYOUN bicycle inner tube is a maintenance accessory designed for 18-inch tires, making it a suitable choice for standard, city, or folding bicycles. Crafted from natural rubber, this special edition tube features a reinforced structure that helps it withstand mechanical shocks and high compression during your rides. To ensure a reliable experience, the tube incorporates an optimized design for uniform inflation, which is highlighted by a green-red graphic marking on the packaging. This attention to air distribution helps you maintain consistent tire pressure for a smoother journey.