The Bilstein B16 2006 BMW Z4 M Roadster Front and Rear Performance Suspension System is a high-performance suspension system designed to provide superior handling and ride quality for the 2006 BMW Z4 M Roadster. The system features Bilstein's patented mono-tube gas pressure technology, which provides a more responsive and stable ride at all speeds. The system also includes a progressive spring rate, which helps to reduce body roll and improve cornering performance. The system also features adjustable dampers, allowing for fine-tuning of the suspension for maximum performance. The system is designed to improve the overall performance of the Z4 M Roadster and provide a more enjoyable driving experience.