|Company||Alerting Communicators of America, American Signal Corporation|
|Sound output||135 dBc at 100 feet|
|Succeeded by||T-135 AC/DC|
The P-50, later known as the RM-135 and T-135-AC, was a rotating, electromechanical siren produced by Alerting Communicators of America and later American Signal Corporation. The rotor and stator are shared with the Cyclone. It holds the title of the world's loudest dual-tone siren as well as the loudest electric powered siren.