1. Our 14 x 2.125 bike tube adopts rubber, high temperature resistant and anti-aging.Its air tightness, elastic damping and anti-aging properties are better than rubber. Thick rubber absorbs impact and you won't feel bumps and dents 2. Compatible Size14x2.125 (ie 57-254) replacement inner tube is suitable for vehicles with 14-inch outer diameter tires and tire widths between 1.90 and 2.125 inches, suitable for most 14-inch tube electric bikes, bicycles, e-bikes, for Jetson and for Gotrax electric scooters and other electric scooters of the same size 3. 14x2.125 Inner Tube with Bent Valve14 x 2.125 inner tube with metal with high air tightness, antize, heat resistant, sturdy and , long using time up to 180 days with an inflation. 4. Fine hingBike replacement inner tubes have clear lines on the surface, highly elastic, and wear resistant.manufacturing process fully meets the standard requirements, stable performance, long life, reduce the occurrence of tire blowouts and air leaks, and eliminate the pain of frequent tire replacement, tire repair, and tire inflation.