Our 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) quartz clocks and silvered aneroid barometers. Polished to a high finish and stove lacquered. Instruments measure: glass diameter is 3.5" - overall face diameter is 4". Mounting board measures 13" x 6.75". Overall projection from wall is just under 3".