1.  Governor control, that assures a closing speed of 6" to 24" per second, has a lifetime warranty.
2.  Fusible link.
3.  Torsion springs designed for 20,000 cycles standard
4.  10" brackets made with 1/8" (min) steel standard on all sized doors
5.  Interlocking slats
6.  Box shaped steel guides for a clean and professional appearance
7.  Tubular steel bottom bar conceals the locking mechanism
8.  Heavy duty cast iron gears
9.  Door can be easily tested and reset from one side of the door.
10.  Approved for all wall types (concrete, masonry, steel, steel with gypsum board).
11.  Available in up to a 3 hour rating.
12.  Release mechanism parts designed to provide years of testing without maintenance or repairs.
13.  Door can be tested in fully closed position without damaging the mechanisms.