The cut out has first (4) and second (5) walls and a fold line (6) with two lateral sections (11a,11b) that are staggered one from the other and displaced by a fixed distance. A middle section (13) of the fold line is displaced transversely with respect to the lateral sections.A central fold line (15) is included, together with two closing flaps (16,17). On a second wall, two pairs of fold lines (19a,19b,20a,20b) are positioned. These are displaced at the same spacing as those of the lateral and middle sections of the first wall.
展开▼