The Ames M300 is a double check detector assembly (DCDA). It is available in 2 1/2″-10″ sizes and has been in production since 2000. The body is made of stainless steel. The M300 has used multiple devices as the bypass assembly but currently uses a 3/4″ 2000BM3. In 2014 a lead free version (LFM300) was introduced.