The Riviera instruments have heavy solid brass cast casings, opening portholes with bevelled glass fronts and a single scuttle clamp closure. Holes for fixing to a bulkhead or wall are hidden inside the case making fitting easier and keeping the outer case neat. Good quality movements - battery operated (one x AA) silvered aneroid barometers. .Polished to a high finish and stove lacquered.Measures: diameter 5"x depth 2.25".