This high-quality butyl rubber inner tube is designed for mountain bikes. It is available in various sizes, including 26*1.5, 1.75, 1.95, and 2.125, with American valve and French valve options. The tube has a thickness of 0.87 mm and comes with an instruction sheet and color box packaging. Please ensure the correct size and valve type before purchasing. The inner tube should be used inside the outer tube and not inflated alone, as this can affect its service life. It is a sealed air bag that cannot bear high tire pressure and depends on the outer tube.