<p>Please check the original inner tube size before purchasing to ensure compatibility. This inner tube is made of high-quality butyl rubber and features an American valve. It is designed for 12-inch BMX bikes and comes with a valve length of 32L and a fetal wall thickness of 0.87mm. The product includes one instruction sheet and color box packaging. Note that the inflation of the inner tube alone may be greater than the outer tube, which can affect its service life. Almost all inner tubes will present uneven thickness when inflated, but this will not affect normal use.</p>