TK Series NEMA 4X Industrial Enclosures Altech TK Series NEMA 4X Industrial Enclosures feature a small to medium size and are completely insulated. These corrosion-free enclosures protect electrical and electronic components from dust and water. Altech TK Series NEMA 4X Industrial Enclosures consist of 15 enclosure types in a broad range of sizes and a variety of cover heights. There are many fixing points for PCBs in the base and these enclosures are ideal for control equipment and measuring equipment.