Lift-Gasfeder (ISO9001: 2008)

The lower mounting bracket stays in the same place throughout. The nitrogen gas inside the cylinder expands and pushes the piston out. The piston makes a tight seal as it slides along the cylinder. The piston moves the piston rod outward. Seals keep the lubricant oil and the gas inside the spring. The lubricating oil greases the piston as it slides out. The piston supplies a useful force as the spring releases its energy (helping you raise the trunk lid, chair seat, or whatever it is connected to).