【SIZE】20"x2.125/2.40" 32mm schrader valve bike tire tubes fit 20-inch wheel，tire width between 2.125/2.20/2.25/2.30/2.35/2.40 in.Applicable models such as Road Bike,Track Bike,Cyclocross Bike,Mountain Bike,Cruiser Bike,Fat Bike,BMX Bike and more. 【High Quality】High quality inner tubes are made of butyl rubber.More resistant to aging and high temperature than natural rubber.It has a service life of 5 years, which is twice that of ordinary inner tubes.The good air tightness of butyl rubber allows each inflation to be held for 5 to 6 months.Ordinary rubber needs to be re-inflated once every 1 to 2 months. 【Heavy Duty】Our inner tube is thicker than other ordinary inner tubes.The thickened inner tube ensures a smooth and comfortable ride.Significantly reduces the sensation of bumps you get.At the same time, the tear resistance is also much better than other products. 【Replaceable parts】Our package includes an additional 5 valve cores and 2 dust caps.Replace them easily and quickly with the included valve core wrench for long-term good air tightness.Aluminum dust-proof cap, high strength, scratch-resistant, can effectively prevent dust from entering the valve tube. 【Package Includes】Two pieces of 20"x2.125/2.40" inner tubes, 5 replaceable eco-friendly valve cores, 1 valve core wrench, 2 aluminum alloy color dust caps. 1