Tyco SimplexGrinnell is often listed as the largest fire protection company in the world. Specializing in active fire protection systems, communication systems and testing, inspection and maintenance services, they have 160 district offices throughout North America.
In 1976, Tyco purchased Grinnell Fire Protection, then bought Simplex Time Recorder Company in 2001. The companies were merged to SimplexGrinnell. It is now Johnson Controls.