cargo trolley also called moving roller skids steerable machine skate means three points roller skate roller skids crawler type means go straight roller skate Shan Dong Finer Lifting Tools co.,LTD produce all kinds of cargo trolleys professionally for more than 20 years. we can produce follow cargo trolleys: go straight cargo trolley, turntable roller skids, crawler type roller skate, steerable machine skate, veered moving roller skids, geared roller skids, and so on. According to the wheels materials of the cargo trolley, it have follow kinds: PU wheels cargo trolley, nylon wheels roller skate, steel wheels machine skate. PU wheels cargo trolley can be used on normal cement floor, will not hurt the cement floor. Steel wheels machine skate have strong capacity and long working life, but need to be the steel floor, or U-bar floor, or it will hurt your cement floor. Nylon wheels roller skate the performance between the PU wheels cargo and steel wheels roller skids. Regarding the roller skids price, and cargo trolley manual instruction please feel free contact with us. hope we will get your satisfaction someday. Shan Dong Finer Lifting Tools co.,LTD Email:sales@cargotrolley.com http://www.cargotrolley.com/