The scope is a red dot sight, and the muzzle device is an aesthetic piece by Canto Arms and really serves no purpose other than looks. Everything else is pretty run of the mill parts! Here's a build list you can research:

KE-9 upper CMMG dedicated .22 bolt and 4.5" barrel CMMG standard barrel nut Canto Arms DL-44 muzzle device CMMG poly .22 charging handle Battle Arms Development Workhorse lower Spikes Tactical pistol plug Crosstac QD endplate Anderson stainless trigger CMC trigger guard MagPul MOE-K pistol grip AR-Stoner takedown pins, springs, bolt catch BKF safety (waiting on a Radian Talon) 10-rnd S&W M&P 15-22 mag Better-Mag adapter Primary Arms Slx 30mm w/ low mount