The Federal Signal MS4000U Siren is a simple, compact 100 watt siren that can be mounted in pretty much any vehicle.  The amplifier is separate from the two rocker switches, so the amp can be installed in a hidden location and the switches mounted covertly.  

The siren provides wail, yelp, air-horn, manual , and Priority tones.  This siren is a 100 watt amp and will drive one speaker only.  There is no PA function with this siren.

The Manual/Airhorn switch is Momentary (push & hold), while the Wail/Yelp switch is Latching.  Priority tone occurs when in Wail or Yelp and the "Manual" button is depressed momentarily.

Designed to be simple, compact, and easy to use.  These sirens have been popular for over 20 years and continue to prove how reliable and popular they are.

• 100 watt compact siren amplifier
• input voltage;  9-15vdc
• Input current (max);  10 amps
• Dimensions of amp;  1.3" H x 6.3" W x 5.7" D
• Shipping weight, 3 lbs
• Warranty;  3 years
• Includes; amplifier, 2 x rocker switches, switch bracket

Manufacturer website is HERE

User Manual is HERE