408 3/16 x 1/4 Half UnionThe 408 3 16 x 1 4 Half Union is a brass adapter that features a male flare connection on one end and a half union (female flare) connection on the other. This adapter is typically used to connect two different sized flared tubing systems, providing a secure and leak proof transition between flare fittings. Specification Details TYPE Half Union DESIGN Half Union Design one end of the adapter has a union connection to accommodate a female flare fitting