Lift supports are pressurized cylinders that are used to support hoods, hatches, trunks, rear window glass, and more. Gas-filled, these hydraulic rods lose power over time and need to be replaced. Quality Strong Arm struts are custom engineered and manufactured beyond industry standards to provide smoother operation and longer-lasting performance as opposed to competing and no-name-brand lift supports. These are the product of amazing American Craftsmanship.For best results, we recommend you replace lift supports in pairs when applicable.