The Thunderbolt siren consisted of three major components: the blower, rotator and siren chopper. The Thunderbolt was introduced in 1952 and discontinued in the early 1990s. It was advertised as having constant volume regardless of pitch. In Late 1988, Federal Signal introduced a single-tone siren called the 2001 Series and the Thunderbolt was phased out by 1990.
There were 3 models manufactured, most of them producing approximately 125dBsound pressure level at 100 feet (30 m):
Model 1000, a single-tone siren capable of two signals (alert and attack). (126dB at 100 feet)
Model 1000T, a dual-tone version of the 1000.
Model 1003, a dual-tone version with the added capability of producing a High-Low or a "Pulse" signal with solenoid valves.
Model 2000, A Single-tone thunderbolt 1000 with a gasoline-powered Roots Blower
The "System 7000" line was a generator back up version of the Thunderbolt. These were available as 3 separate models:
Model 7012, a single-tone siren capable of two signals (alert and attack).
Model 7022, is the same as Model 7012, but is dual tone.
Model 7026, which uses a dual-tone Thunderbolt siren to produce six siren signals: wail, pulsed steady, steady, alternating steady, alternating wail, and pulsed wail.