Machined from Extruded 6005A-T6 Aluminum and Type 3 Hardcoat Anodized, Class2 Deep Black, making it a durable and robust design with ultra narrow diameter. Patented Anti Slip & Anti Rotation system, strengthens the handguard in the receiver end area and allows strong clamping onto the barrel nut. The handguard cannot be removed from the barrel nut without removing all three fixing screws.