Ruger's AR-556 semi-automatic rifle is made from froged aerospace-grade 7075-T6 aluminum. The hard coat anodized, flattop upper receiver includes a forward assist, dust cover and brass deflector, while the handguards are made from heat-resistant glass-filled nylon. It has a carbine-length, milled gas block with multiple attachment points for a QD socket, bayonet lug, and sling. Serrations on the angled face of the gas block provides a low-glare surface. The Rapid Deploy folding rear sight provides windage adjustability and the front sight post is elevation adjustable, and includes a front sight tool. The A2-style F-height allows co-witness with many optics. It also has a bolt machined from 9310 alloy steel, single-stage trigger, chrome-plated bolt carrier with a matte black oxide finish on the exterior, and patent pending barrel nut and Delta ring for one person handguard removal and installation. This model has a black six-position buttstock and handguard, and a Magpul PMAG.