The Eibach Pro-Spacer is a 5mm wheel spacer designed for the 84-91 BMW 325i (E30). It is constructed from high-strength aluminum alloy with a 4x100 bolt pattern and a hub center of 57.1mm. This spacer helps to improve the vehicle's handling, cornering, and stability by creating a wider track width. It also increases the offset of the wheel, allowing for a more aggressive stance. The Pro-Spacer is an easy and cost-effective way to improve the look and performance of your vehicle.