Receiver integrated ARCA rail; SIG-designed compensating muzzle brake; 3 Moa Romeo2 red dot installed on RX2 model; Lower receiver compatible with all MCX upper receivers; Magpul SGA stock – Mossberg 500/590/590A1; Fully ambidextrous mag release, safety selector and bolt catch; Reduced weapons visual-IR signature Gen II NiR FDE Cerakote