Uni-box enclosures are constructions that are a safe and aesthetic product for mounting low voltage units, "S" type fuse units, single and three-phase meters, control devices as well as other electrical devices. The enclosures are made of PC plastic (polycarbonate) in the color gray, equipped with a seal that allows for high tightness parameters, a perforated mounting plate, doors in gray or transparent on hinges closed with one or two locks with a key. Versatility of use and carefully made elements in the end result in a solidly made and aesthetically-looking housing.