AET Barrel Option:
Accuracy Enhanced Technology. Check this page for more info. AET barrels feature a Titanium Nitride Coating: main purpose is to increase surface hardness to reduce rifling wear from projectiles.
The AET barrels are a little more selective on the ammo you use. Don't spend the extra money on an AET barrel and the shoot low grade ammo and expect top performance. I have both AET and non-AET barrels and like both. For IPSC its a personal choice, you can win with either.
Barrel:
As this is the Standard / Limited Sight tracker template you don't have a choice here.
Rib without holes is also called hybrid barrel without ports, its the same.
Caliber:
You probably know what you want, if not buy one of each and find out by trial and error ;-)
Compensator:
Again not an option for the Limited / Standard Guns but here's a picture of what the standard 9x19 comp looks like.
AET Barrels are Golden Bronze colored
