2. How can I tell if my handguard has the "standard" barrel nut?
Take a look at the image of the barrel nut on our site. The ID threads are standard across the board that screw on to the upper receiver. The OD needed is 47MM X 1.0 thread pitch. This come standard on pretty much all AR15's.
All the aftermarket handguards you see utilize this nut assembly. They are not included with the CoolTubz'
We offer the barrel nuts for sale if you need one as an ADD-ON item.