Here's a YouTube video showing the plug. I'm referring to the plug that goes into the device, of course. Not the normal AC plug on the power supply unit itself.
I'm considering buying a device that uses an AC/DC power supply (the device in the video, in fact). However, the plug at the end of the power supply's cord is a little unusual and if something happens to the supply, I don't want it to render the device useless.
So I'm looking for either the possibility of buying a similar power supply, or an adapter which I could connect to a regular supply. But I don't know what this plug is called so I can't even search for it.