四轮滑冰鞋

每个人都可以在这个公园内溜冰。

roller mangle having moving flat table

roller and compactor【公路】

roller bearing ball

hinged-slat roller shutter (roller shutter with slats disappearing in each other)

guide, roller, cable

printing roller turning and roll-finishing machine

arc furnace tilt roller track【冶】

roller and apron device for combing machines