Sparco Wheel Spacer 20M 4X100 56Id What To Do With An Old Air Compressor Motor at Jennifer Hooper blog. Sparco Wheel Spacer 20M 4X108 65Id Made from a special aluminum alloy, Sparco wheel spacers are forged from an innovative process that produces a high strength to weight ratio. Each wheel spacer is then put through a CNC machine to obtain an extremely flat surface. All wheel spacers are heat treated to further increase strength and anodized to guarantee protection from oxidation. Reference the 'WHEEL SPACERS APP GUIDE' to determine the proper part number for your vehicle. **Wheel spacers may look different from pictures due to different make model applications. Technology Special aluminum alloy Forged and heat treated for ultimate strength CNC processed for a perfectly flat surface Anodized to prevent oxidation