Developed with input from the professional instructors at SIG SAUER Academy, the SIG SAUER M400-SDI X AR-15 Semi-Auto Rifle delivers the highest level of performance and reliability. Featuring fully ambidextrous controls, including a bolt catch and release, the M400-SDI X is easy to operate for both right- and left-handed shooters. The free-floating M-LOK handguard features a new steel lockup design that reduces handguard deflection by providing maximum rigidity and allows for adding accessories on all 4 sides without negatively affecting accuracy. Finished off with the 2-stage Matchlite Duo trigger that delivers a 4.5 6.5 lb. pull weight with a flat blade, the M400-SDI X sets a new benchmark for performance in an AR. The Magpul SL stock provides enhanced cheek weld and easier shoulder transitions. Mid-length gas system with low-profile gas block. Barrel with SIG flash hider-compensator. Includes one 30-round magazine. Fully ambidextrous controls Free-floating M-LOK handguard with dual-clamp locking system Barrel with SIG flash hider-compensator 2-stage Matchlite Duo trigger with 4.5 6.5 lb. pull Mid-length gas system with low-profile gas block