Stacker crane generally perform a wide range activities such as lift and transport skids, bales and baskets, load and unload trucks, stock shelves and handle dies, molds, or pallets. By combining a power lift with an easy to operate manual push. They are offered in widest range features and differ in operation. Hydraulic stackers are featured with heavy duty steel frame, dual heavy duty lifting chains, the hydraulic system often chrome plated ram relief valve for over load protection, hand controlled floor brake to secure the unit in place. The standard specifications of hydraulic stackers offered are standard capacities, load center, lowered and raised fork heights, adjustable straggle legs, fork size, casters, fork adjustments, front wheel and battery. Manual stackers are also available and can be used in a wide variety of applications such as work positioning to improve ergonomics in the workplace.