It is a mechanical type rolling shutter. It shall be fitted with ball bearings. A crank handle is a winding handle for pulling and pushing mechanical gear-operated shutter.

If the rolling shutter is operated by a bevel gear-box and crank handle, it can be used upto a maximum of about 25 m² clear area.

These type of shutters generally use worm drive arrangement. It means the worm drives the worm wheel fixed to one end of the roller. The worm drive gives a safeguard against any accidental falling of the curtain because of spring failure.

The gear box operates the worm by a straight shaft connecting the top of gear box and worm. The crank handle of the gear box can be removed. If customer wishes, the crank handle operation shall be given on both the sides of the wall.