Did a google. Seems like TWR is correct pretty much. Should be fine for non top line build up.
FWIW I've seen errors with top line brand names and seen "junk" lowers run just fine and vice versa, but if after top of the line function and accuracy, one can never go wrong by spending a bit more to get known names. Least they'll stand behind it all.
And as far as I know, most all lowers are all done by continental machining and stamped whatever is desired. CLE even has a run of lowers now and again.
JEff
