Stock buffer tube for M&P 10

[wanker]

Just curious, I am thinking about removing my prs, and getting a CTR stock for range time. The original buffer that came with the rifle had the stock fixed, and I had to drill it out - and then threw it away. That being said, I now need another buffer tube.. Is there anyone in particular I need to get size wise? Or will just any buffer do to replace?

Thanks as always.

-Wanker.