D's race proven low friction X-Rings. D's PRO-Street VX Series Chains are a perfect match for your dual sport, sport bike or sport touring bike. D's PATENTED X-Ring construction reduces friction by twisting between the side plates instead of being squashed. Normal O-Rings and 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. 1.5 to 2 TImes Longer Wear Resistance. The X-Ring's 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.