4.5 mm Socket Driverthe worlds largest line of professional RC tools first and best RC tools, imitated by others, but never duplicated! used by all RC factory teams and champions totally unique lightweight tools with very light non slip hollow duraluminum handles and a new unique everlasting diamond pattern grip that cannot be copied CAD designed tips designed to precisely fit the fastener to prevent rounding the corners or marring a nut tips are hand made from special