JARD Mil-Spec AR Barrel Extension Bit Socket Black. Milled to fit snugly our bit socket provides solid contact and maximum engagement for torqueing. Additionally this tool can also be used for barrel nut installation or removal in conjunction with a drive extension. Maximum lug engagement 1/2" drive socket Milled from 4140 steel Specifications for JARD Mil-Spec AR Barrel Extension Bit Socket: Manufacturer: JARD Fabric/Material: Steel Color: Black Package Contents: JARD Mil-Spec AR Barrel Extension Bit Socket JARD 5109: Mil-Spec AR Barrel Extension Bit Socket Black