MEZ H1/B2 siren is a high-tone mechanical siren, being the second most common mechanical siren located in Czechia. It has 9 ports, and can be found in two different roof covering variants - single and multi layer. It can be also rarely found without a covering, usually under a separate roofing. All of the options are usually made of sheet metal or different types of metals.

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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, but It shares a very fast start-up to full speed (approx. 1 second) with the Fm Si 41. The siren also runs on three-phase power, and may used as a fire protection siren only, which is found to be common.

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In the Czech Republic, there are 208 sirens registered within the JSVV (Jednotý systém varování a vyrozumění - Unified warning and notification system), from which there are 187 sirens actively in use. (as of 17/6/2021)