Geissele’s Super Duty Stripped Upper is an ideal addition to any custom AR build, and offers the quality and craftsmanship that all Geissele products are known for. It comes equipped with a Super Duty Upper seamlessly attached to a 15” MK16 Super Modular Rail via center aligning tap to eliminate any chance of rail rotation. The barrel is cold hammer forged, chrome lined, and coated in manganese phosphate to ensure superior durability, performance, and a long service life. Features: Super Duty Upper15” MK16 Super Modular RailCold hammer forged, chrome lined, manganese phosphate coated barrel Geissele Automatics Geissele Super Duty 5.56 NATO 16" 1:7" CHF Bbl DDC Stripped Upper Receiver w/15" M-LOK MK16 SMR 08-247S