McVitie Weston valve collection, STC Micromesh valve, type R.2.
STC Micromesh valve, type R.2., (RMW/A146 - McVitie Weston number), by Standard Telephones and Cables Limited.
STC Micromesh valve, type R.2., (RMW/A146 - McVitie Weston number), by Standard Telephones and Cables Limited.