The VFC QRS Stock adjusts easily by pressing the latch and finding the right size for you along the buffer tube. You can also open the butt pad which has ample room for any type of battery and makes things easier when it comes to battery changes. The stock suits all Mil-Spec buffer tubes.There is a small rail system on the bottom for a vertical pod making it easier for you to balance your rifle if you are using it for a sniper system. You'll find a sling mount on the top, rear of the stock.