Product Introduction Hydraulic vehicle positioning jacks allow a single person to move cars, trucks and ATV's around the repair facility with ultimate flexibility. There is no need to jack the vehicle up and place dollies under each tire, as each unit combines a Hydraulic jack and dolly together in one simple piece of equipment. Perfect for moving vehicles under repair or restored automobiles in confined spaces, dollies allow cars to roll backwards, forwards and sideways easily.
What features do these double acting hydraulic cylinders china has? The answer is there are many features of the double acting hydraulic cylinders. They are very common hydraulic cylinders which use both the oil ports and the oil entering while the both direction is controlled by the pressure of the oil. http://www.blogster.com/hydrauliccylinder/chinese-hydraulic-double-acting-cylinders