The Derya TM22-A-18 is a semi-automatic, .22 LR rimfire rifle manufactured by Derya Arms in Turkey and imported into the United States by Rock Island Armory (RIA) / Armscor. TM" stands for TradeMark 22 (or Total Metal depending on the specific metal-receiver construction context), designating Derya's line of .22-caliber platform firearms. The "-A-18" denotes an aluminum-receiver variant featuring an 18-inch barrel. Built to mimic the ergonomic layout and handling of an AR-15 style rifle while utilizing a simple blowback-operated rimfire system, the TM22 series was introduced to offer a budget-friendly tactical plinker compatible with select AR-pattern accessories (such as grips and buffer tube components).