The 2X shock absorbers are designed for the front of BMW 1 and 3 Series F20, F30, and F31 models such as 118d and 318d manufactured from 2011 onwards. They are gas-charged shocks with a twin-tube gas pressure system, providing a smooth and controlled ride. The shock absorbers are made of steel and come with a 3-year warranty from the seller DREXLER. These high-quality shocks ensure 100% accuracy of fit and are sealed for durability and performance.