I presume this is the product that you are referring to: IC Graphite Thermal Pads | Innovation Cooling which comes in 30x30 or 40x40 size.
If you have the Ryzen CPU, try measuring one side with a MM Tape or Inches tape (convert to MM) and see which of the two sizes above is closest. Or measure the CPU Cooler Heatsink surface and see what size it is.
The Manufacturer does say that the IC PAD is electrically conductive so you need to be aware of this when installing the Pad.
Curious, why do you want to install a PAD and not Thermal Paste? A Pad normally is used if there is a small gap between the CPU Cooler Heat sink and CPU surface. But if it is a tight fitting without any gap, I believe, Thermal Paste will be better than a pad.
PRO & CONS of using Thermal Paste vs Thermal Pad:
Copied from second link:
Other Types of Thermal Interface Materials vs Thermal Paste
Thermal Pads vs Thermal Paste
You could also find thermal pads in the market. Although they are easy to install, the fact that they don’t perform well in conducting heat is what makes thermal paste superior. In most cases, you could find them in stock or prebuilt computers.
Thanks for your useless anwser but i juste need to know witch one can i insert between my rad and cpu.
Just because i cant find the size of the top of the cpu.
So no there are nice stuff and reusable so that pretty cool.for my bench.
There only 1degree diffrent with a noctua nt-h1 for the average same price.
LoL, all you have to do is measure one side of the top of the Ryzen CPU where the CPU Cooler heat sink goes to get the size pad you need.
Maybe another User with the same Ryzen CPU can measure it for you and give the size you need or has knowledge of the size of the CPU surface.