4371 Louvred roofing (2) Roof covering of interlocking extruded aluminium louvre blades, with powder-coat or anodised finish, rotated electrically or manually to provide a weatherproof roof with the louvres in the closed position but admitting light and air when the louvres are open 4372 Pneumatic roof covering (0) Roof covering of inflated ETFE cushions constructed of translucent materials held in aluminium carriers and spanning without intermediate support between main roof structural members, with each cushion attached to a compressed air line to maintain inflation