【Environmental Butyl Rubber】: The scooter wheel is made of butyl rubber, which has high temperature features(-60℃-180℃), excellent anti-permeability, ageing resistant and durable, butyl rubber will not scratch and distribute harmful gases, it is a great substitute for Xiaomi M365 or other scooters with 8.5inch tires. 2mm thickness inner tube, Outer diameter 8.25 inches, inner diameter 5.5 inches, width 2 inches. Universal for front and rear wheel, a perfect spare wheels for scooter【Widely Used】: The spare tire set do not leave marks and respect all types of floor surface, its mute, damping, anti slip and wear-resistant effect increase the comfort for scooter on the road and lateral stability and heat dissipation. Rubber ribbed surface features in.