|Company||Sentry Siren Incorporated|
|Sound output||127 dBc at 100 feet|
|Frequency||460 or 920 Hz|
The Defender was a rotating siren produced by Sentry Siren Incorporated. It produces either 460Hz or 960Hz, depending on customer preference. Like other Sentry models, it was available in stainless steel for added corrosion resistance. It was discontinued due to low sales and Sentry's preference for omnidirectional models.