Federal Signal 2001 Series evolution

The 2001 Series has been around for almost 4 decades. In that time, its design has evolved quite a bit. Timestamps: 0:00 | Intro 0:06 | Scope of video 0:12 | 2001-SRN (1st gen.) 0:46 | 2001-SRN (2nd gen.) 1:21 | 2001-SRN (3rd gen.) 1:55 | 2001-SRN (4th gen.) 2:31 | 2001-SRNB 3:06 | 2001-130 3:41 | Equinox 4:16 | End of video Credits (in order of appearance):    • Federal Signal 2001-DC Roundback Siren Tes...   [PENDING]    • Federal Signal 2001-DC | Short Alert, Poll...   [PENDING]    • Chicago Tornado Siren Test   [PENDING]    • Athens, GA Federal Signal 2001-SRN Test Fe...   [PENDING]    • Federal Signal 2001-SRNB | Alert | Vevay, IN      • Federal Signal 2001-130 | Noon Blast | Sei...   [PENDING]    • Lansing, MI | Federal Signal Equinox | Ale...   Siren wiki: https://web.archive.org/web/202504201...