Milwaukee Twins Crankcase Breather Assembly Milwaukee Twins Faceted Crankcase Breather Assembly has a one-piece filter molded to a light weight chrome faceted cover. Includes a chrome plated zinc die cast mounting base, a 5/16 inlet which accepts 3/8 breather hose. Features: One piece filter molded to a light weight chrome faceted cover Includes a chrome plated zinc die cast mounting base 5/16 inlet for use with 3/8 breather hose 2 diameter filter