what size hole for rear turn signals?

[MikeD1980]

ok, here's the deal. my bike is 1/2 hr away and I am going to make a bracket for my rear turn signals, but need to know what size holes I need for them to mount through. I don't have one laying around to measure they are with the bike. if someone could be so kind to measure the threaded part on one and let me know what size hole I need to drill it would be greatly appreciated!