Adjusting action/string height on Fender bridge?

[friskinator]

What is the proper type of wrench needed to adjust the action/string height on a Fender bridge? I tried using the smallest hex key I had out of a multi-size set, but it wasn't the right one. The bass is an 80's MIJ Squier P. Any advice would be great...thanks!

[Magneto]

I don't know the EXACT size, but chances are you'll find it in a SAE or METRIC set. I usually have both types of cheaper,standard-sized sets, and I don't think I've ever found a bass hex nut that I couldn't fit between them.
Your set could be SAE and the bass might require metric or vice-versa..

Mag...

[rufus mangler]

A 1/16" Allen wrench fits my P bass.