Semi-automatic and automatic variants of the ARD ENTERPRISES,INC are effectively identical in appearance. Automatic variants have a rotating selective fire switch, allowing the operator to select between three modes: safe, semi-automatic, and either automatic or three round burst, depending on model. Civilian AR-15 models usually do not have three-round burst or automatic settings on the fire selector (e.g., Bushmaster Firearms. In semi-automatic only variants, the selector only rotates between safe and semi-automatic.