This type is suitable for relatively small openings whereby a mechanical or electrical mechanism is not necessary to operate the Roller Shutter Door.

Doors of up to 24 square meters are operated by an endless-chain wheel through a reduction spurgear fitted to the helical coil spring barrel.

By means of preference, a gearbox can be fitted in place of chain operator.

At basement parking, high risk security areas, doors that are constantly operated through the day at irregular intervals an electrical operator is recommended.