The front drum brake on early Big Twin and 45CI models is notorious for its lack of stopping power. The single cam design has one leading and one trailing shoe and consequently brakes equally when you ride forward or backward. You hardly do the latter but want more stopping power when riding forward. This double cam or "duplex" brake, with its close-to-stock looks design gives you two leading shoes and consequently provides the stopping power where you need it. Kit includes brake drum, brake drum cover, brake shoes, springs, cams and so on. Fits 1936 thru 1948 Big Twin and 1941 thru 1957 WLC and Servi-Car. Relatively easy to install, but check clearance with the rocker shaft nuts.