Great accessory , instructions below - FAB Defense MBA Mono-Pod Buttstock Add-on

This is a cool addition , well made, not rock solid but definitely helps. If anyone is wondering if you can swap the base pad for a different style, the answer is yes . You will notice there is no release button (for the pad like it is on the stock). It is more or less a friction fit. Push down from the top and it will slide off. I had to tap mine with a nylon hammer to get it started but it was simple enough. Some instructions in the package would have saved me some head scratching trying to figure it out.