From Wiki: In Germany and some other European countries, the pneumatic two-tone (hi-lo) siren consists of two sets of air horns, one high pitched and the other low pitched.
From Despicable Me:
From Wiki: In Germany and some other European countries, the pneumatic two-tone (hi-lo) siren consists of two sets of air horns, one high pitched and the other low pitched.
From Despicable Me:
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