A large domestic military enterprise: mainly engaged in military aircraft manufacturing, repair, maintenance, etc. Before 2008, their castors were all self-made, because the castors produced by domestic caster manufacturers could not meet their requirements. They require that the load of a single wheel must reach more than 3 tons, and the driving force is small, the impact strength is high, the wear resistance is not flammable, etc. In 2008, we provided starlight industrial casters: high strength nylon wheel and PF polyurethane wheel for testing and trial use. After their strict testing, they fully meet their requirements.