Number of installations for Pro only for one device?

Mongoose

So considering snagging pro but curious about one aspect. I see that it says that there's 5 installations, and I am curious-- is this per one device, with the license mated to it, for use only on that one device?

I am curious because I have 5 Raspberry pi's, and 11 3D printers. I'm wanting to set 2 printers per device and then have the respective webcam feed. I know you can use a hub, but I am wary about overloading the pi's with too much going on, and trying to mitigate the effects if a host crashes.

So-- if you have a Pro license, can you install it on 5 different devices just once, or can you install it on just one device 5 separate times? 

Repetier

You can split it on 5 devices of course. This was also meant so you can do one installation on your pc to speed up slow calculations that pi's can then outsource to your pc if that is active.

Mongoose

Thanks!