Good product but a few things you should know - Sylvan Arms AR15/AR9 Gen3 Folding Stock Adapter

First of all, this stock adapter works exactly as advertised. It's good quality and let's you fold your AR platform to fit in a smaller space to carry. I used one that was pre-installed on a 9mm AR with a 5" barrel and it's perfect for folding up and throwing in a backpack. I decided to buy one to build a 556 lower. As expected, it adds some length and weight. It was very easy to install but a few things to consider. You'll need a second castle nut. It comes with the one pictured for the side that mates up to your lower. It doesn't come with with the castle nut that goes on the buffer tube side, so you'll need that if you are doing a new build. You'll also need a thin castle nut wrench to tighten the receiver end, there isn't much room to use a heavy duty one. Next thing to consider, the buffer retainer set screw on the buffer tube side is pretty small. If you take it out, remember that spring is under a good bit of tension and will go flying if your not paying attention..you can probably figure out how I know. Last, and I probably should have figured this out, but you need to use the BCG extension for this to work so you pretty much need to go with the traditional buffer and spring. I bought an Armaspec stealth recoil spring that I planned to use on this build and quickly realized that wasn't going to work with this device.