The Noveske N4 SPR Lo-Pro 18" 6mm ARC Complete Upper Receiver is a premium, 4th-generation AR-15 upper assembly meticulously engineered to maximize the long-range ballistic potential of the 6mm ARC cartridge. Built on a precision-machined billet 7075-T6 aluminum receiver with a durable Armor Black Cerakote finish, it features a heavy 18-inch 416R stainless steel Special Purpose Rifle (SPR) barrel. This match-grade barrel incorporates a hand-polished chamber with extended M4 feed ramps and a smooth, consistent rifle-length gas system designed to deliver optimal reliability and sub-MOA precision. The complete assembly comes outfitting-ready with a 15-inch free-floating NSR M-LOK handguard, a 5/8x24 threaded suppressor-compatible "Pig Pen" flash hider, a dual "Love Handle" ambidextrous charging handle, and a full-auto rated phosphate carrier housing a premium DLC-coated 9310 steel bolt. Delivering exceptional durability and flat-shooting accuracy, this elite flat-top component group drops seamlessly onto any standard mil-spec AR-15 lower receiver setup.