I know this is a crap post, so sorry in advance.

I bought this jig, and a portion of material had to be machined off before I could use it, because it did not fit the Shadow Ops 80% lower I bought. I don't have the jig at the moment (I don't even know where it is actually), or I'd take some pictures and show you what I mean. It's no big deal at all since removing material from the jig is the same thing you're doing to the lower anyway. Sorry I can't be more specific at this time.