Product Information: Long service life; Optimal fitting accuracy for easier repairs; Strict quality standards; Compliance with the requirements of vehicle manufacturers. Vehicle Repairs. We've Got What It Takes. The bonnets of many vehicle models are not held open by a support rod which must be latched in by hand, but rather by a gas spring. The pressure inside the spring makes it easy to open and close the bonnet. To prevent the bonnet from closing on its own, the gas spring must be precisely adjusted to its weight and position. febi offers a comprehensive range of gas springs in the best possible quality. Ferdinand Bilstein relies on constant premium quality for gas pressure springs with a long-standing aftermarket partnership with original equipment supplier, Stabilus. Quality by Conviction. The gas spring consists of a piston rod and a cylinder. When the bonnet is closed, the piston rod presses into the cylinder, compressing the gas. When the bonnet is opened again, the gas expands and holds the bonnet up. In order for gas springs to be fully functional, the gas inside the cylinders must not escape. In order to guarantee 100% tightness, febi gas springs are intensively tested. Our quality management tests the offered replacement parts for various requirements and loads. These include accuracy of fit, dimensional accuracy, material quality, tensile strength, and compressive strength.