The transparent modules (1A, 1B, 1C) can be of a rectangular or triangular shape with their edges folded in a right angle alongside (2) resulting in longitudinal joint areas (5), and provided with reinforcing ribs (3) in their centers. Each of the joint areas (5) comprises several openings (6) for the insertion of screws, securing the joint areas (5) of two adjacent panes (1A, 1B, 1C) to each other.