Excellent light - SureFire M640DF Scout Light Pro Dual Fuel LED Weapon Light

Light performs as advertised. Plenty of throw to help with target identification at short-medium distances. Able to see reflective eyes of deer across a hillside during a dark misty evening.

So far so great. I mounted the light on the Pic rail just behind a Troy flip up front sight at the front end of a 13" BCM M-Lok handguard, BCM vertical foregrip over a 16" barrel. The light fits just to the left (I'm right-handed, so my support hand can C-clamp the front of the rifle at the perfect spot to thumb-activate the button).

Gets snug enough, leaving only a small gap, close to the handguard and can rotate in just to where the light just touches the front backup iron sight.

The rechargeable battery is weird, it has a charging cable that's too short in my opinion but will work fine charging the battery hanging off a wall socket.

Best with handguards that have a full Picatinny rail on top.