AK 47 STANDARD FLAT MOUNT REAR STOCK ADAPTER. Our new AR stock adapter makes it easy to add a two bolt style (ACE) stock, Choate stock or our modular, custom billet, Galil, rear stock to your AK47 pistol using our thin adapter between the grip and the receiver. Two threaded holes have 10/32 threads, also fits the ACE type flat mount stocks. Fits most AK/ LYNX/HELLPUP pistols.