The SIG SAUER M400-SDI XSERIES packs a rich set of features and upgrades into the M400 platform delivering an advanced performance rifle right out of the box. The M400 XSERIES lower features fully ambidextrous controls, including bolt catch & release, selector switch, charging handle and mag release. Also unique to the XSERIES is a precision machined lightning cut upper and lower with a handguard clamp system designed to minimize deflection when using mounted accessories. FeaturesHybrid flash hyder/compensatorSIG Flatblade 2-Stage Matchlite triggerMagpul SL telescoping stockAmbidextrous bolt catch and releaseLow profile gas block with mid-length system