Dumpster polyurethane on poly wheel is made of polyurethane tread and PP core.PU surface is soft with great with ductility and elasticity,which can absorb shock and vibration to protect floor.PP core possess high firmness.And this caster is tested and verified to meet 12 hours neutral salt spray exposure.In addition,PU is low-toxic and odorless, belongs to Eco-Friendly material,and can be recycled.This PPU caster suggest for almost all kinds of floors and for a variety of applications.