Powerful FAR Insert tool for M4 to M8 or 4-40 to 5/16-18. Installs by pulling with semi-automatic load of the insert. Constant and perfect installation every time. Adjustable stroke. 2 trigger system prevents inserts from jamming on the mandrel. Tough and long lasting tool. Sold with 5 UNC heads or 3x Metric heads depending on your preference.