Features:Made of butyl rubber， durable and wear-resistant.High air tightness， needn't waste too much time on pumping tire frequently.Designed with American valve， easy to pump tube up.Suitable for tube specification of 26 * 1.9/2.125.Specifications:Material: Butyl rubberColor: BlackType of valve: American valveInner tube thickness: 0.73mmProduct size: 26 * 1.9/2.125 in (diameter * width)Product weight: 146g / 5.1ozPackage size: 7.5 * 6 * 9.5 / 3 * 2.4 * 3.7inPackage weight: 165g / 5.8ozPackage List:1 * Bicycle inner tube