John Guest 3/8" to 5/16" reducers are designed to give the ultimate in adaptability and life long leak free solution to reducing from 3/8" fittings to a 5/16" outlet.
They are suitable for reducing an existing 3/8" push fit female fitting to allow use of existing or accessory 5/16" lines when needed.
They are suitable for a leak free connection to existing lines and connectors with our Micromatic Secondary Regulators on both input and output sides as well as bulkhead conenctors or any other application with 3/8 inlets or outlets. (see the pics below)
Pics are indicative of potential uses.