Maple Leaf Crazy Jet Inner Barrel 300mm for MARUI VSR-10 - AnodizedMaple Leaf designed a barrel where the end is wider compared to the rest of the barrel. At the end of the barrel the air will pass the BB and come out first and when the BB comes out of the barrel, the air stream pulls the BB in a so called jet stream. This will have less resistance on the BB and will NOT decrease the velocity but increases Accuracy instead.