Sig Sauer RM400SDI16BP M400 X-Series 5.56x45mm 30+1 16" Black FNC Chrome Moly Steel Barrel, Black Anodized Aluminum Receiver, 15" M-LOK Handguard, Synthetic Magpul SL-K Stock, Black Polymer Grip
The M400 X-series features a free-floating M-LOK handguard, Magpul SL-K 6-position telescoping stock, Sig Flat Match Grade trigger, 16" Chrome Moly barrel, and a 7075 T-6 aluminum receiver with a black hardcoat anodized finish.