Output Jack Ring is Loose

[SquierVM]

I am new to bass, so bear with me. The output jack ring (the place where the cord goes) on my new VM fretless is loose. I have been told that this is easy to fix, just tighten it with a wrench. Does anyone know what size wrench would be optimal for this?

[SC Bassboy]

It is probably a 1/2. To tell you the truth though, at this point I can just look at something and instinctively know which socket to use. Rarely do I actually look at the size. But I think its 1/2. Should be the easiest thing to repair on a bass.

[newfuture]

Yep, it's either 1/2" or 12mm, very close in size to one another. One thing to make sure of is when you tighten the nut to not over tighten it, or let the jack inside spin (this can break the two wires soldered to it), so I'd take the control plate off and hold the underside of the jack if you sense it's beginning to spin.