[MrForbes]

I assume you are talking about this Festo solenoid valve?

It came in a bag with some wires and 3 round metal fittings that screw into the holes (where the arrows are in the picture). Two go on the top, one goes on the bottom in the middle. The round metal fittings have no way to grip them on the outside, but they have a hex shaped hole in side that you can fit a hex wrench into.

If you are talking about something else, please describe it or take a picture, so we can try to help you