The Vertiv Liebert Transformer Distribution Unit (TDU) is a step down transformer / voltage converter that provides 120VAC output power from 208VAC or 240VAC input. It accepts 208 or 240VAC (200/220/230 VAC acceptable) input and converts it to 120VAC (L-N) output. The 3440VA/3440W TDU is designed to work with Vertiv Liebert GXT3-6000RTL630, GXT4-6000RTL630, GXT4-3000RT208, and PSI5-5000RT208 but can be used with other UPS products with 208VAC in & out, and have a compatible input power plug.