Required number of horizontal stiffeners for grouting into side walls. There is
one horizontal stiffener around 300 mm from the top, one around 300 mm from the
bottom and more if required, to maintain a distance of not more than 1300 mm vertically.
Hold fasts and bolts for fixing stiffeners to side walls.
A G channel with slots for louvers for right hand side, a G channel for left hand
side and required number of middle G channels, to maintain a distance of not more
than 800 mm between two vertical G channels.