We produce Minimalist Concrete Roster of various models with a size of 20x20 which can be used as home ventilation which improves air circulation and can save electricity. Roster can also be used as interior and exterior partitions of the house so that it sweetens the room and gives a broad impression.By installing a concrete rooster as the second skin of the building (secondary skin) on the facade of the house, sunlight can be filtered out so that only part of it is transmitted inside the house. Likewise with the air and wind around the house, concrete rooster is a good circulation path for these two elements so that the temperature in the house feels cooler and cooler.