Pairs of horns usually come in two tones: low, as the one on the left above, and high.

http://www.stebel.it/stebel2009/products.asp?IDserie=3&uso=&tipologia=ELECTROMAGNETICS

Click on HQ audio to hear a sound clip.

Last edited by Gambalunga; 26/06/12 11:28 AM. Reason: spellink
Peter

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