Shame I haven't found another purpose for these toolholders, got three spare brand new plus one I only use for 1/16" shallow cut ie o ring grooves.
To tighten the things its like driving a wedge on to the top of part tool of variable distance depending on height of tool.
Never had mine work loose when had to use it, the main problem even when grinding up neutral, left hand or right hand with a bought Eclipse blade, it always veered off in direction of that Eclipse side relief. You can see the actual blade bowing plus laterally.
Used Sandvik for years then got handed a load of Iscar, Arno, Manchester, Seco part off tools rarely used on a 5 axis they came from. Got think 7 or 8 permanently setup in qr holders, need more. If you are going to buy one part off tool do your homework as there are that many styles and designs, same with the interchangeable tips not only conventional neutral, left or right hand but different cutting patterns and grades for specific materials.