Marpac Gas Spring Hatch Lift - 12 Inch Retracted - 20 Inch Extended - 120 PoundsMarpac Gas Spring Hatch Lift 12 Inch Retracted 20 Inch Extended 120 Pounds Stainless steel. Socket End Style. The ideal solution for lifting, lowering and counterbalancing weight. The gas spring is a self contained, nitrogen driven counterbalance product which provides uniform handle forces, non catastrophic failure and many years of service. Because energy is provided through gas pressure, our gas springs give you repeatable, unvarying performance