Noveske Rifleworks LicensedNoveske NSR-7.0 M-lok handguardCGS ( CYMA Gas System ) provides reliable performance and durabilityCompatible with all standard Tokyo Marui MWS M4 spec partsMain Material : Aluminum, Zinc Alloy, Nylon FiberSystem : Gas Blowback, Adjustable Hop-Up, Marui MWS compatiblePower Source : Green / Top gas