This AR15 Armorers wrench is for real firearms, but is necessary when working on lots of todays AEG M4/M16 variants. This tool is constructed out of solid metal, and features the following;
Buffer Tube Castle Nut Wrench
Muzzle Device Wrench
Delta Ring / Barrel Nut Wrench
and most importantly, it has a 3/8" drive for a torque wrench ensuring proper barrel nut torque.