The FEBI-BILSTEIN 40-221595 Air Suspension Spring Rear 15.5" x 15.15" x 8.45" B3 OE Replacement Air Series is engineered to restore the original ride quality and handling characteristics of select BMW X5 and X6 models. This air suspension spring is designed to replace the original equipment (OE) air springs, ensuring a seamless fit and reliable performance. Constructed with high-grade materials, it offers enhanced durability and longevity, effectively addressing common issues such as sagging or uneven ride height caused by worn-out air springs. By maintaining consistent air pressure, the FEBI-BILSTEIN 40-221595 ensures optimal vehicle stability and comfort, even under varying load conditions. Its precise engineering allows for rapid adjustment to road and driving conditions, providing uncompromising comfort and driving characteristics. This air suspension spring is a cost-effective solution that helps minimize downtime and maintenance costs, contributing to improved fleet productivity. Compatible with BMW X5 models from 2007 to 2013 and X6 models from 2008 to 2014, it is a direct replacement for OE part numbers 37 12 6 790 078, 37 12 6 790 079, 37 12 6 790 080, 37 12 6 790 081, and 37 12 6 790 082. Installation is straightforward, connecting directly into the original connectors without the need for modifications, ensuring a hassle-free replacement process.