advanced technology, arm with no rotation, complete machine Non-outrigger design could pass across obstacles like machine tool to catch material and lift, widely used in more areas; Standing operation, operator moves with machine, easier and convenient; Arm extend and return electrically at 600mm, easy and simple to catch and lift material; American Curtis electric controller, continuously variable driving speed, 24v battery power, recharge battery in night, crane could work for 5-8hours in day time; Electric trolley crane could be used to lift device, emergency, machine lifting and rescue.