This is not a muffler more
This is not a muffler more. The original is manufactured by Advanced Armament Corporation, and is dedicated to use by US Special Operations Forces (such as DEVGRU in missions such as Neptune's Spear).
One of his most defining characteristics is its use as 'Window Breaker'. And to this detail it has been taken into account when being replicated in airsoft by PTS Syndicate as we have seen in A2D.
The piece to break glass has been manufactured in CNC steel with a finish in dark gray designed to fit into any silencer 37.5 mm in diameter but probably only meets the aesthetic function.