Gas springs and shock absorbers open and close doors, hatches, access panels, and other objects at steady and controlled speeds. They contain pressurized gas or liquids that provide smoother movement and make them less prone to wear than coiled metal springs. Gas springs, also known as gas struts or shocks, supply pushing or pulling force for lifting, lowering, and supporting objects such as vehicle tailgates, trunks, and machinery hatches. Shock absorbers, also called dampers, slow the motion of doors or lids, so they close gently and quietly to avoid damage.