The ACE AK Compact Receiver Block helps you attach multiple different stock options for your AK. You can also get different sling attachment points for your preferred setup. In order to install this receiver block you will have to make some easy, permanent modifications to your AK. The tang on the back of the receiver must be cut off then filed or ground smooth. The internal receiver block will then simply bolt into the receiver. It will be connected at the pistol grip screw hole on the inside of the receiver and the pistol grip T nut will hold the front of the receiver block. There is no movement to the receiver block once it is installed. Fits most common stamped receivers, 1mm and 1.6mm.