Width is 50mm (75mm with mounting tabs)
Height is 40mm
Depth is 40mm
Input is 110V/220V. Output is 12V
This is an AC transformer and the output is AC also.
If you need DC you need a power supply not a transformer.
If you try to measure the output using the DC setting in your meter it would not give you a voltage.
You need to set it to AC in order to measure the output voltage.