The mechanism of this J55 Heavy Duty System is similar to the Pulley Chain system, controlled by a similar chain and does not contain any spring within the system (Figure 1). As the name suggest it is more robust and has capability of supporting a larger weight of the fabric, as compared to other systems.
It is also ideal to be fitted outdoors as it is sturdy enough to withstand strong winds.
Since the blinds used in this system can be huge, rather than using a ball chain, an endless chain will be used. Meaning the chain would passed several times through the control more during extend or retracting.
Ideal maximum dimensions as follow:
Indoor - Max Width 2.8m/ Max Height 5.0m or Max Area Max Area 8m²
Outdoor - Max Width 2.5m/ Max Height 3.5m or Max Area Max Area 8m²
Ideal maximum dimensions is Max Width: 2.0m/ Max Height 2.5m or Max Area 4m², whichever is smaller.