Auto-Transformers, mounted in steel-cases with a handgrip.
For matching and operating of 110 … 120V-units at the 230V line voltage.
An auto-transformer has only one winding with a tapping, there is no insulation from mains.
For protection against short-circuit and overload a changeable fuse is incorporated.
The input has a 2m mains lead with a mounted
Schuko-plug. The output has a US-socket.