Unit substations are designed to convert distribution voltages to utilization voltages and can be used outdoor or indoor for commercial and industrial application. The switchgear on the low-voltage side of the transformers may be located in a building, with medium-voltage circuit breakers or electrically operated or manually operated disconnect switches for distribution circuits, along with metering, control, and protection equipment. For industrial applications, a transformer and switchgear line-up may be combined on a fabricated steel structure and called a unitized substation or USS.