Greater rigidity (7% higher than previous VM). Higher rigidity creates smoother handling, reduced power loss and quicker response. Highest value in all D.I.D series. D.I.D X-Ring has half the friction compared to O-Ring chain. Superior longer life than previous VM series. Replaces the Professional O-Ring V Series and the Premium X-Ring VM Series. Average tensile strength 8,210 lbs.. Suitable for use up to 800cc. Includes clip link. 520VX3 Chain 520 x 112, Gold/Black