Model M

Model M
[[File: Sterling M-5 in Mantua, Ohio. |200px]]
Company	Sterling, Sentry Siren Incorporated (later)
Produced	Late 1910's - late 1980's
Type	Electromechanical

The M series was a series of sirens made by Sterling. They usually either came in 16/16 port or 8/16. They commonly came in 2 models: The M-5 and the M-10. The M-5 and M-10 are discernible by their rotors: The M-5 was the most common and had smaller rotors than the M-10, which features larger rotors; however, many M-5's are often mistaken to be M-10's. Model M-5 featured a 5-horsepower motor, and Model M-10 featured a 10-horsepower motor.

There was also a single head variant produced; the M-3, which had a 3 horsepower motor. These sirens were often mistakenly called "N-5's", until the real model name was discovered.

The M-series was produced from the late 1910's up until the late 1980's, first by Sterling Siren and later on by Sentry Siren after they acquired Sterling. The M-3 and M-5 were discontinued prior to the 1980's; and sometime in the late-1980's, Sentry Siren Incorporated discontinued the last model they produced, the M-10, in favor of the 10V2T. The M-series is known for its reliability and durability, and many communities still use M-series sirens to this day, some of which chose to use M-series sirens over more modern sirens due to their durability. One of the advantages of the M-series was its simple design and operation, which made maintenance easy and relatively simple.