Huge Investment Opportunity! For the serious collector, finding a single authentic Heckler & Koch HK416D upper receiver in civilian hands is a monumentally rare achievement, as these elite systems were strictly restricted to military and tier-one law enforcement contracts. To discover a consecutive, sequential pair-specifically, Serial Numbers 88-001643 and 88-001644-is the absolute "holy grail" of modern military firearms collecting. Born from HK's legendary contract lineage to revolutionize the AR-15 platform, these uppers represent the pinnacle of combat-proven engineering. These units feature highly sought-after 2005 "AF" date codes representing the coveted early-era production of the platform. Complete with their factory 14.5" barrels, iconic short-stroke gas piston systems, authentic HK 9" quad rails, and fully matching, original HK-marked OBT Bolt Carrier Groups, this pair stands as an incredibly rare, museum-grade investment opportunity that commands center-stage in any world-class collection. An important thing to note. These were NEVER sold to civilians. And the 14.5 spec is significantly rarer than 10" models. Just for reference, HK Parts is selling these uppers OTB for $10,000 each! So the starting bid for 2 sequential uppers is a STEAL! (View Last Photo) Specifications Overview Heckler & Koch HK416D, Upper Stamped Serial #88-001643 Complete Upper 5.56mmx45 AF Date Code Upper Receiver (2005) 14.5" Barrel Indirect Short-Stroke Gas Piston HK A2 Flash Hider HK 9" Quad Rail All Standard HK Proof Marks HK416 Complete Bolt Carrier Group OBT Adjustable Fixed Front Sight Adjustable Flip-Up Rear Sight (Troy Industries) Heckler & Koch HK416D, Upper Stamped Serial #88-001644 Complete Upper 5.56mmx45 AF Date Code Upper Receiver (2005) 14.5" Barrel Indirect Short-Stroke Gas Piston HK A2 Flash Hider HK 9" Quad Rail All Standard HK Proof Marks HK416 Complete Bolt Carrier Group OBT Adjustable Flip-Up Front Sight Adjustable Flip-Up Rear Sight