NB size refers to the external diameter of the metal roller tube
Comes with either a never ending chain.
The chain length is either
1m which makes a drop of 500mm
2m which makes a 1m drop
3m chain which makes a 1.5m drop
4m chain which makes a 2m drop
5m chain which makes a 2.5m drop
6m chain which makes a 3m drop
You will get a free safety device with each roller kit, which must be used.
All continuous chains must be secured using a chain tensioning device which must be fixed to a wall at least 1.5m above the floor.
To calculate maximum allowable chain length to comply with new safety regulations:
Max drop of chain = (Height of rail from floor in cm - 150cm)
MUST BE FITTED WITH A SAFETY DEVICE