This kit allows precise adjustment of the primary chain and creates less drag and loss of power resulting from the stock spring loaded assembly. This new manual primary chain tension aduster kit is ideal for bikes equipped with big displacement high performance engines. Permits manual selection of primary chain tension and is a direct replacement for the original equipment automatic version. The anodized billet aluminum adjuster allows you to fine tune and lock settings. The manual adjustment locks the chain tension in place to prevent free play during severe shifting. Kit includes mounting hardware. Required seals and gaskets not included with adjuster.