This simple looking device consists of a tiny 40 x 25 x 19mm module with 300mm leads connected to each end. On the input side there is a 22AWG terminal block for connecting a 24V AC or DC source. On the output side, there is a 2.1mm DC plug where you have a regulated 12VDC supply, at up to 300mA. The AC input can be 20 - 28V, and the DC input can be 16 - 30V.