MK12 KAC Freefloat rail - $365 shipped - SOLD Picture 1 MK12 Front Sight (KAC) - $125 shipped Picture 1 MK12 Geissele SSA-E $185 - shipped MK12 Allen Engineering Collar&Brake $125 shipped - SOLD Picture 1 MK12 Centurion Barrel 18" SPR $425 shipped - SOLD Picture 1 Picture 2 MK12 Rear...