AFCO Racing's 16 Series Twin Tube smooth or threaded Circle Track shocks offer shim stack technology in a small body design for open wheel cars—Sprint, Midget, Mini-Sprint, and Micro racers. The shocks are rebuildable and repairable. Stay on track with AFCO Racing Circle Track 16 Series smooth small or threaded body shocks. Available in a 5 inch, 6 inch, 7 inch, 8 inch, or 9 inch stroke.