This is the "R" line of AM chains, the top tier quality, offering exceptional endurance for heavy duty. Special design of reinforced sealed-in lubrication makes AM sealed chains work to its optimum life in tough situations. Superior reinforced alloy steel is adopted and heat-treated to provide the best performance in strength. In addition, specially formulated grease, contained by a durable ring between solid bushing and hardened pin, keeps constant lubrication and extremely eliminates friction during operation in hard, demanding situations. The reinforced construction ensures least wear, resulting in minimal chain stretch and prolonging its service life in the most challenging conditions.