losacero 25 is a system developed for use in metal mezzanines slabs in buildings, optimizes the construction time to eliminate the use of traditional falsework, because it allows simultaneously casting the mezzanine and roof, all this translating into savings of time and money in their works. This ribbed design provides a more aesthetic appearance and especially its application apparent. Savings volume of concrete is another important factor both by cost and by total weight of the system. It is picklable (anidable) and traslapable and therefore optimizes space in transportation and construction site.