Signal Sirens are specially designed to give you centralized control with all the features you require to provide both power and safety at your fingertips. Ability to run at 200 Watts for extended periods Selector knob for phaser, yelp, wail, hands free, alert, manual and radio modes Separate volume controls for radio repeat and public address functions Public address override on all modes Meets class A & GSA specs. Siren is backlit for easy nighttime readability L 6" / W 6.5" / H 2.5" 100 or 200 Watts (1 or 2 speakers) Voltage: 10-16 VDC Frequency: 675-1633Hz Amp. Draw: 8 Amps (per speaker) New Feature: Automatic Circuit Protection New Feature: LED Speaker Diagnostics New Feature: High & Low Voltage Protection New Feature: Positive Locking Connector With Wire Harness.