I was really impressed with this little kit! If this is the same one that I purchased the kit comes with several little #4X40 set screws and the tap that threads the hole as well as the little allen wrench to install the screws once the rear takedown hole is threaded. I couldn't believe how easy it was to do the install and afterwards you don't have to worry about loosing parts because of the detent spring going flying across the room every time you remove your butt stock. Also this is so simple that a child could do this install with very little challenge. This is definitely worth the price because of everything that comes with it and because of all of the time it saves not having to look for springs and other parts. In fact that is what I am doing now is trying to find this part so that I can buy more of them! THANKS SO MUCH (T-I)