The 100 kVA REX auto transformer with copper winding is a rugged voltage conversion unit engineered for reliable step-up/step-down power conversion between 220 V, 380 V, and 480 V systems. Designed for industrial and commercial electrical systems, it delivers high efficiency and dependable performance where electrical isolation is not required. Built with premium materials and tested to North American standards, it ensures stable voltage adjustment for a variety of power applications.