The Rainier Arms flattop upper receiver (minus forward assist) is carefully machined to mil-spec to serve as a great foundation for a quality .22 LR or 9mm AR-15.
Made from 7075 - T6 aluminum
Type III hard coat anodized
Matte black finish
Dry lube coating: Inside to reduce wear and adds lubricity
"T - Marked" engraved
Compatible with Ciener style BCG (Ciener, CMMG, Tactical Solutions)