http://sirennet.com/whfr.html The Whelen Freedom Rota-Beam Series Lightbar is a "Cutting Edge" version of the Freedom Lightbar that is built using the new Rota Beam modules. The Rota-Beam module is designed to imitate the classic rotator effect without the maintenance problems and high current demands of motors and halogen lights. The Freedom Rota-Beam Series Lightbar is built on the same Rugged extruded aluminum I-Beam construction of standard Freedom lightbars.

Features:
Base configuration includes 4 Rota-Beam corner modules.
Add up to 5 Rota-Beam inboard modules, 2 Front and 3 Rear, or 3 Front and 2 Rear.
400 series modules may also be added to your configuration where space is available.
Build your lightbar in any color combination with take-downs and LED modules in any position you want.
Takedowns and alleys can be single or dual LR11 modules.
Clear outer lenses are standard.
Available with Scan-Lock flash pattern control that lets you toggle through the multiple flash patterns and lock in the pattern you select.
Every pair of lights can have its own unique pattern.
Rugged extruded aluminum I-Beam construction.
All models meet or exceed SAE Class 1 and California Title XIII requirements.
External control cable included.
15 foot cable, passenger side exit.
Standard Lengths: 44", 50", 55", 60", 72".
Size: 3-3/4" (95mm) H x 12" (304mm) W.

Whelen Five Year HDP (Heavy-Duty Professional) Warranty on LEDs