RK Racing Chain 530XSOZ1-128 Steel 128-Links RX-Ring Chain with Connecting Link 530XSO chains feature heat treated hi-carbon alloy steel components with seamless rollers and shouldered bushings, and are fitted with RK's proprietary RX-Ring seal design 530XSO chains offer quality, performance and unbeatable value, for all but the most demanding high performance application RX-Ring technology offers less torsional friction, increased high-stress performance, and a 30 percent longer wear life compared to standard O-ring chains Viewed in cross-section, the X-ring has two lubrication pools and seal points versus the single seal point/pool design of a regular O-ring chain 530XSO has a maximum tensile strength rated at 9500 foot pounds and is suitable up to 1000cc street bikes and 750cc off-road bikes