12, that is a hard question.I use several different traps for coon,and when I have a coon in them,they are great.
I like #1 1/2 coils,#11's,#1 coils and on my rat houses the #1 stoploss,all have caught and held coon over 30 pounds.
When I trap coon on land,I use coon cuffs and in urban areas 12"x 12" x 36" cage traps.
All have a good record when catching coon.But if you are not on location with your set,it doesn't matter what you use--you will not catch them.
Tom