Check the listing for details. FSA Micro ACB Headset Bearings Bundle Durable Stainless Steel Cartridge. Condition: New. Listed at 43.95 USD. Optimize your bikes performance with this premium bicycle headset bearing bundle featuring the FSA (Full Speed Ahead) Micro ACB Gray Seal 36x45 Stainless Steel Headset Bearing and the FSA Standard Headset Bearings. Crafted for durability, precision, and smooth steering, this collection is essential for cyclists seeking reliable components for their zero-stack headsets and steering systems. High-Performance Materials & Engineering Constructed from stainless steel, these bearings offer excellent corrosion resistance and longevity, making them ideal for both road and mountain biking. The sealed design helps keep out dirt and moisture, ensuring consistent performance in all weather conditions. Advanced Components & Technology The FSA Micro ACB Gray Seal Headset Bearing features a compact 36x45.