Features - Ultra lightweight carbon fiber barrel construction - Durable aluminum alloy thread sections - Common 14mm counter clockwise (negative) threads for mock suppressors, flash hiders and tracers - Adds a custom look without the added weight Outer barrel piece mainly made from carbon. Available in 3 lengths to match our "M4 outer barrel base" to form 5 inches, 7 inches, and 9 inches overall barrel length. Also compatible with our series of standard AEG, NGRS, M4 GBB, SIG AIR MCX, and MPX outer barrel base (total length of the barrel may vary by the chosen barrel base). Our "M4 Barrel Piece" can be utilized to adjust the overall length. Manufacturer: Laylax / First Factory Specifications: Length: 108mm (Muzzle thread length excluded) Weight: 27g Threads: 14mm Negative (CCW) Compatibility: For Laylax outer barrel bases Material: Aluminum, Carbon Fiber Disclaimer: - This product requires the outer barrel base to be installed. - Overtightening the product may cause the product to break. - Please make sure to use an inner barrel which is as long or longer than the outer barrel. - We recommend to tighten the barrel after the inner barrel has been installed to the outer barrel piece.