Upgrade your stock laydown/layback Associated B6.3-B6.2 top shaft with the Exotek B6.3 Locked Spur Mount Set. This lightweight mount features a titanium center bolt and is perfect for 17.5 stock buggy and high powered street eliminator drag racing. Easily switch between a locked spur or slipper depending on track conditions. Compatible with multiple spur gear sizes from Exotek and Kimbrough, weighing only 5.1 grams including hardware.