The Milwaukee M18 FUEL? 1/4? Lockbolt Tool with ONE-KEY? Hucktainer? Fastener Adapter is made from proprietary steel to ensure durability and provides the capability of installing 3/8" Hucktainer Fasteners by making a simple and quick swap with the Adapter included on the M18 FUEL? 1/4" Lockbolt Tool with ONE-KEY?. This item is compatible with the MILWAUKEE? M18 FUEL? 1/4" Lockbolt Tool with ONE-KEY? (sold separately).