For off-road applications where a sealed chain is preferred, D.I.D's 520VT2 X-Ring chain provides excellent low friction high performance. D.I.D X-rings offer half the power loss and 1.5 to 2 times the wear resistance of a normal O-ring chain. Narrow design for motorcycles that can't accommodate a wider sealed chain due to clearance limitations. Weight per 100 Links: 3.65 lbs.; Tensile Strength: 7,610 Lbs.; Maximum engine displacement: 500cc. Rivet Type Master link included. D.I.D's patented X-ring construction reduces friction by twisting between the side plates instead of being squashed. Other makers modified O-rings have squashed points that increase friction. The twisting action of the X-ring disperses the pressure and minimizes power loss, while the four contact points greatly increase its sealing performance. This keeps the dirt out and the lubrication in much better than any other O-ring. X-rings have the greatest wear resistance of any other type of O-ring or non-O-ring chain.