This is the Aero Precision M5 AR-10 Assembled Upper.

Features:

• Superior Construction: Crafted from aerospace-grade 7075-T6 aluminum.
• Precision Engineered: According to Aero Precision, each unit undergoes stringent quality checks.
• Forward Assist & Ejection Port: Pre-assembled with a forward assist and ejection port cover.
• Corrosion Resistant: Finished with a hard-anodized black coating to offer resistance against wear, abrasion, and corrosion.