MEZ | H4/A2

MEZ H4/A2 siren is a high tone, high performance version of the H1/B2, manufactured by MEZ ("Moravské elektrotechnické závody" eng. Moravian electrotechnic works) . Alongside of H1/B2, it is one of the most common mechanical sirens located in the Czech Republic. It has 9 ports, and can be found with two different roof cover variants - single and multi layer cover (three sheet layers). It can be rarely found without any covering, usually hidden under a separate roofing or any other types of solid covers. All of the covering options are usually made of sheet metal.

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The MEZ siren, compared for example to the DS977, Fm Si 41 or KIRKE has a significantly higher tone of 435 Hz, and shares a very fast wind-up to full speed (approx. 1 second) with the Fm Si 41. The siren runs on three-phase and single-phase power. The H4/A2 type sirens were used as mass warning devices, and are still being used as such, although they are aged and outdated and are currently slowly being replaced by modern electronic sirens.