What is the deepest large coil for Minelab Pro SE

[Roadquest]

Got my Minelab Pro SE. Learning it over again. Had one a few years back. I took it out
on some land my brother owns in McKenney Va. for a couple of hours. Found 3 Civil War Bullets
And some junk. I like this detector. Just want a deep coil. I know some of you guys can advise me on this.

Thanks RoadQuest

 

[Longhair]

Big coils have their drawbacks unless the ground is basically clean of trash items.
That said, the Coiltek 15" WOT or the SEF 18" Q² will likely be the deepest.