Fits perfectly - Primary Arms SLx 5X Prism Scope Anti-reflection Device

The kill flash fits perfectly on the 5x acog by Primary Arms. When I started to screw the kill flash in to place, I thought maybe I got the wrong one, but it was just the fine thread not aligning to start. Once started, it spun freely till it got to the halfway point. From that point the threading tightened up considerably. Once it bottomed out, the kill flash lined up perfectly with the scope making for a solid, firm fit that looks good. Haven't experienced any issues since. It hasn't backed off or loosened and so far, perfect.