Replacement sight clamp bolt fits all Knight's Armament Standard Front or Rear flip up iron sights. Sold individually.
#99051 MK12/MK18 Front Sight
#97082 300m Rear Sight
#98474 200-600m Rear Sight
#22243-1 RAS 2, this is the cross bolt for the rear clamp where the handguard mounts to the upper receiver.