Works great with a standard ar buffer - JP Enterprises SCS System Buffer Retainer Pin & Spring Kit

I purchased this simply because I wanted a more robust buffer retainer pin. Unlike many of the reviewers, I only use normal AR buffer/spring setups, not the self-contained ones. It's beefy, and I have confidence it will not break. It is also easier to push down for disassembly and maintenance due to it's large retaining surface. Overall a great item do have for a heavy-use gun.