These instruments have brass cases with super durable, tarnish-free coating (see explanation below). Single scuttle clamp closing. Case diameter 7", depth 1". Quartz clock movements use one AA battery.
About Tarnish-free - Our new ranges of super durable...tarnish-free instruments have been coated with a newly developed protective coating using advanced surface treatment technology. This new coating, far superior to lacquers and varnishes, can withstand more than 720 hours (the longest test period for this process) under NSS (Neutral Sea Salt) laboratory testing. NSS testing is a certificated and standardised test method used to check corrosion resistance of coatings on metals such as brass, zinc and steel.
It is an accelerated corrosion test that produces a corrosive attack on the product coating from which the results can predict its suitability for use as a protective finish. These instruments will resist tarnishing even when exposed to the harsh marine environment for extended periods.