Crafted from lightweight aircraft grade 6061 aluminum. Standardized design works with almost all LR-308 builds. The package includes an aluminum barrel nut, castle nut, and anti-rotation set screw. All Monstrum Tactical LR-308 Quad Rail Handguard products are backed with a lifetime warranty. Note that the aluminum barrel nut is significantly lighter than steel barrel nuts, however it may be subject to damage during installation. We recommend using no more than 35 pounds of torque during installation. This barrel nut is not compatible with the DPMS GII rifle. To confirm whether this barrel nut will fit on your rifle, please click here to refer to our AR-10/AR-308/LR-308 Handguard Compatibility Guide