The Rock Island Armory (RIA) M1911-A1 FS (Full Size) is a popular, affordable .45 ACP pistol known for its classic design, reliable performance, and value, featuring robust steel construction, a 5-inch barrel, and Series 70 internal design for a crisp trigger, often coming with upgrades like ambidextrous safeties, beavertail grip safeties, and better sights than original GI models, making it a solid entry into the 1911 platform for defense, sport, or collecting.