From The Manufacturer/Wikipedia/People Smarter Than Us:
The DTI Extreme Duty has a 16″ hammer forged CMV chrome lined barrel with 1×7 twist, M4 mil-spec stock, M4 handguards with double heat shields, and A2 flash hider. The Extreme Duty also features Troy DOA rear folding sight. The rifle also comes with 1 x 30rd magazine and a CA approved Gun Lock. Ships with a Chamber Safety Tool in the chamber, showing clearly the weapon is unloaded.