I think he means specifically the Tactical Lite buttstock itself that XLR uses on their chassis. As in just the stock piece that would fit on a buffer tube. Don't know of anything similar though.
OP: I think the round buffer tube XLR uses on their chassis would work on an AR, I belive it's just a buffer tube with the locking slots removed. Why not call Kyle and ask him or PM him here, his username is XLR. He'd be able to tell you if it would work or not.