... traveling mechanism,crab+trolley hoist and top quality electrical appliances.Heavy duty double beams bridge crane.We are expert on crane, pls inform ... working condition, we could supply you the best suitable type!For the double beams overhead crane, it has the follow features!QD ... appliances, and could be classed into several working duties, for instance:A5,A6 A7 and A8 according to the working ...