A few days back, I had a chance to pick up a AK-12 stock set. The stock feels incredibly solid. The four position buffer tube is not based on any western standard and will not fit AR-15 stock systems. The rear buttpad sits on a dovetail, and is held in place by a spring loaded detent which is released from the bottom of the assembly. Inside the Buffer tube (and held in place by the buttpad) sits a cleverly designed, compact cleaning kit. These were built to actuate with the AK-12 rear trunnion, but could (I believe) be made to work with a AK-100 series 5.5mm rear trunnion to some degree.
