All gas springs contain a small amount of oil to lubricate the main seal and rod. This oil also provides end of stroke damping.

In order to keep the rod seal lubricated, a small amount of oil is used in every gas spring. When used rod-down, the oil is kept in contact with the rod seal which improves the sealing properties and ensure the seal will never become dry.

For this reason, one of the basic recommendations when incorporating gas springs in your design is to make sure they are used at an angle of less than 60 degrees from the vertical.