Factory bushings are made from rubber compound, which deteriorates over the years. OEM bushings become softer, therefore becoming less capable of resisting the forces being placed on them.Megan Racing bushings on the other hand are 20%-30% stiffer and do not deteriorate in performance over time. The benefit of the increased stiffness will improve driver control of vehicle.- 150% Harder that stock bushings- Made with high-strength and anti-cracking rubber material- Rubber viscosity is around 2000KGS- 2 pcs/set- Professional installation recommended, pressed in tools required