What voltage for mk1 1.8 injector?

Hi, I’ve decided to clean the injectors on my 94 mk1 1.8
I’ve managed to remove them but it wasn’t as easy as the manuals suggest but that’s working on old cars I guess.
I intend to give them a good soak in carb cleaner and a minute or so in my ultrasonic bath but would like to blow some carb cleaner through them afterwards.
Does anyone know what voltage is used to open them? I’m guessing 12 volts but as they are driven by the PCM I guess there is a chance it could be 5 volts.
Anyone know for sure?
Thanks
Dave

They are 12 volts.

Thanks Robbie
Just out of interest some comments say you should put the injectors back in the the same location. Can’t really see why.
Any thoughts?