The oil within the cylinder, when it is compressed or extended, moves from one side of the piston head to the other, providing a damping effect. Weather Guard Saddle Box example # 136-3, 136-3-01, 136-5-01, 156-3, 156-3-01, 156-5, 156-5-01, 158-3-01, 158-5-01, R-136, R-156.
