UEAJ electronic siren series are used for sound coverage of urban and small-town areas, public spaces, stadiums or large halls. They are also used as a part of large-scale systems for the needs of civil defense and emergency services. Tesla UEAJ sirens are the oldest electronic warning devices in Czechia, and also the oldest siren series manufactured by a domestic company. Tesla UEAJ-I sirens are no longer being maufactured.

These series were later replaced by the second-generation series - Tesla UEAJ-II.

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Like the most sirens, Tesla UEAJ consists of two basic parts: electronic unit and acoustical unit, which are connected together. This construction allows the siren to be used both in outdoor and indoor spaces. The electronic unit consists of multiple electronic devices, such as power supplies, batteries, control units, electronic storages and the acoustical unit carries multiple loudspeakers and antennas.

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Tesla UEAJ sirens have not been manufactured for many years. The first row of products assembled in 1997 to 1998 claimed success but had major quality shortcomings, such as plastic loudspeakers, which did not produce a very good sound, and the drivers, which were not as high quality as the ones used in competitive products. On the other hand, UEAJ sirens were assembled with high quality amplifiers.