These M4 x 12mm long Thumb screws are for Upgrade Innovations monitor mounting plates. The .187″ thick monitor plate yields a 7.25mm long screw.
Standard screw length is 7.4mm/.291″.
Use a minimum thread engagement of 1-1/2 times the screw diameter on the threaded insert on the display.
O-Rings are used on Upgrade Innovations monitor mounts that have a counter bored hole at the mounting side with screw holes not bigger than .201″/5.1mm
Max hole size where these thumb screws can be used is .201″
If hole is larger head can pull off Knob and through hole.
When using thumb screws for other plates, you must check hole diameter of VESA plate hole. The holes cannot be larger than 0.201″ / 5.1mm. If holes on your VESA plate is larger, Do Not Use