The specs speak for themselves.
Caliber: .308 Win
Barrel: Floated 22" stainless w/1:10 twist that is fluted
Action: Cooper receiver mounted to a Colt chassis
Brake: Surefire muzzle brake
Trigger: Timney 3lbs
Grip: Magpul MOE - compatible with any AR grip
Colt did mention other calibers were being considered such as .223 and .22-250, however nothing has been decided.