Diamond 530Xlo Rear O-Ring Chains 530Xlo O-Ring chain seals out abrasives and seals in dual lubrication with factory injected, heavy grade lubricant. O-ring lubrication keeps the chain lubricated and prevents premature elongation and contaminants out of the pin/bushing joint. Features oil-impregnated sintered steel bushings. Features: XLO O-ring chains seal out abrasives and seal in dual lubrication with factory injected, heavy grade lubricant O-ring lubrication keeps the chain lubricated and prevents premature elongation and contaminants from entering the pin/bushing joint Features oil-impregnated sintered steel bushings Master Link Installation tool 6000365 strongly recommended for installation Made in USA