This adapter replaces the factory shroud baffle and has M18x1 threads. Comes with thread protector

Instructions:

• remove the factory shroud by grabbing onto the shroud by the front cap. When you turn the shroud counter clockwise, that should loosen the front cap. The shroud is free floating, there are no threads in it. Important thing is to remove the front cap.
  
• once shroud is off, put a few drops of red loctite onto the barrel thread.
• put the shroud back on
• now take new shroud adapter and tighten onto barrel. Let it dry for a few minutes
• remove thread protector on shroud adapter to screw on an airgun suppressor with M18x1 threads.