ProWin Now offers the entire hop chamber unit for your favorite M4/M16
AEG! The ProWin Brand is known to create precision complex-shaped parts
with their refined CNC manufacturing methods which sets it apart from
other brands cast metal method.The CNC milled hop up is made from a
solid piece of stock aircraft grade aluminum which means that the
material completely consistent and eliminates the possibility of bubbles
and weak areas in the metal. Anodized hard treatment in cobalt blue
color adds to durability and that custom look.