The GOG One Piece Carbon Fibre Freak Barrel is an excellent, high quality product. This product unlocks a new level of performance. Freak flexibility and perfect paint to bore sizing is now available with the amazing strength-to-weight ratio of true carbon fibre. This product is built of layered woven carbon fibre composite from its inner bore to its exterior for maximum strength. The classic all-American porting dampens the marker’s sound signature while providing a pathway for propellant gas to equalize with the atmosphere before the ball exits the barrel. This is the nexus of efficiency and strength. This product also comes with a .689 insert. Two threads are available including Autococker and GOG.