The gun has the strap hanger on the barrel and would be an SBR with the stock on it. The website also says it goes on the SMG. Why do you think it's for a semi auto?
https://www.brownells.com/guntech/product-spotlight-jmac-customs-ss-8-folding-stock/detail.htm?lid=18569
It attaches to a Pic rail similar to a SIG MPX or MCX. Seems like it would look pretty cute on an M11/9 too. I suppose it wouldn't be that hard to drill a couple holes in the back of the...
A friend of mine sold a RDIAS for $1000 when the going price was $4000. He was all "har har har" because he got to use it for 5 years and got the same as he paid for it. Wasn't too happy when I told him the straight scoop, and yes, I was pissed that he never told me he was looking to sell.