The mark consists of the unique styling of any firearm consisting of the following: A uniquely tapered and ribbed forearm assembly as per the illustration, made of metal, synthetic or wood; a proprietary method of attaching the forearm consisting of a metal cup, a metal key and a metal spring; a combination front sight assembly and gas port block; a uniquely shaped pistol grip assembly, also of synthetic material or wood; a uniquely shaped butt stock of synthetic material or wood. All these features in combination and corresponding to the illustration represent the "STG" series of rifles as offered by I.O., Inc. .