Word of caution on any suppressor that indexes on the flash hider:

DO NOT use with a flash hider that is not NATO spec or a flash hider that is installed with a split washer or crush washer. The only method that Gemtech "warrants" in their unwritten warranty is use of a peel washer.

I love my Halo, but am now jealous after hearing a friend's SRT in action (SRT Typhoon w/ atlas universal mount). It too has a QD mount that aligns on the A2 flash hider.