Important Facts to Consider: Electro-Mechanical Warning Siren. No speakers or amplifiers here, just real, honest, big-time, worry free sound. 100% Maintenance Free Siren: Just take care of the batteries, and that's it !!! NON-ROTATING. Forget about the worries of rotating sirens, this unit only has two moving parts !! Mechanically produced sound - stronger and further reaching than electronically produced sound. Proven, this siren has been deployed in cities around the world, and is the best selling single tone siren we have. Lifetime Tech Support is included with every siren. No matter how old your siren is, we will help you through any problems. FIVE YEAR WARRANTY so you can rest assured your siren will be functional at all times.** Employing carefully designed horns to project sound over long distances, the 7V8-B is Sentry's newest model. The Model 7V8-B is rated at 118 dB at 100 feet, and like all Sentry weather warning sirens, is OMNI-DIRECTIONAL. The 7V8-B is a single tone siren, producing 460 cycles per second, for optimal sound penetration. The siren can also be custom ordered in 920 hz. The new battery option makes warning available when power is not. The new solar charging option, requires no electrical power, not even for the chargers. Maximum diameter of the Model 7V8-B shall be 56", maximum height of 41", and maximum mounting base of 19" square. Shipping weight of the siren alone is 350 lbs.