This kit eliminates the seals, and increase the life span of the stock Heim bushing. Save your self a lot of money replacing and increase performance with this kit. Plastic composite material is used in robotic engineering equipment for zero maintenance. This will prevent your stock A-Arm Heim bearing from wearing out. They will last 6x longer compared to stock or common Delrin / urethane bushings. No lube or grease required. Completely self lubricating. If your stock Heim bearing is loose, in most cases this will remove the "slop" and increase strength. Longer length than stock to improve contact area and strength at a more affordable price.