The NCstar AR-15 Barrel Nut Crows Foot Tool is specifically designed for GI spec barrel nuts with 1/2" and 3/8" drive compatibility for precise torque specifications during AR-15 barrel installation.NCstar AR-15 Crows Foot Barrel ToolCompatible with GI specification barrel nuts1/2" and 3/8" drive socket compatibilityDurable steel constructionWeight: 8.0 ozEssential for AR-15 builds and maintenance this tool ensures proper barrel nut torque specifications for secure and accurate barrel installation. Compatible with standard torque wrenches for professional results.