Federal Signal's Model's 2, 5, and 7 are probably the most widespread siren in the U.S Edit
All three models have the distinctive cone-shaped housing; with one chopper inside. The majority of these sirens are painted either red; yellow; black; or gray (mostly red). Some models have up to 4 directional cones mounted onto the housing; with the least number being 2. These sirens have replaced most old sirens; and are still in use and production today. Most of them serve for fire calls in the U.S. today.