This item is made for Airsoft only (Made in Taiwan) The Action Army High Precision Tight Bore Inner Barrel brings high quality at a great cost. These barrels are manufactured from High Grade Metal and then machined to perfection! The Action Army Tight Bore is essential for boosting the performance of your Airsoft AEG. Specifications: Manufacturer: Action Army / Made in Taiwan Overall Length:: 370mm/14.57" Inner Diameter: 6.03mm Compatibility: All Marui Compatible AEG's that use Standard type AEG Inner Barrels Features / Application: - Increase Grouping / Accuracy. - Increase Power / FPS. - Increase Range / Distance (Maximum Range / Effective Range). - Made out of High Quality Metal with Electroless Nickel Coating