King Arms, its their flashhider for the SPR rifle...it screws onto the 14 negative tip of the 552, and comes with a setscrew, so I just put it as far back as it goes for the right position, and the setscrew it. I also has a thread protector thats not in the pic. The suppressor is compatible with their OPS MK12 silencer.....
Only thing is that the end muzzle opening for the hider and the opening for the suppressor is too small for the BB to miss, so I had to drill the hider and the supressor out to a bigger size....though another way of solving that issue is to make use the extra length with a longer inner barrel....
