The Apollo DCDA-4ALF is a double check detector assembly (DCDA). It is available in 2 1/2″-12″ sizes. It has been in production since 2011. The 2 1/2″-8″ body is made of stainless steel. The 10″-12″ body is made of ductile iron with a fused epoxy coating. The DCDA-4ALF utilizes a Type I or Type II bypass.