This is a customised Aluminum heatsink for PiGear Nano. You can also use it on other boards with Raspberry Pi Compute Module 4 (CM4).
This heatsink has dimension 55 x 40 x 11 mm, and weights 20g. It perfectly fits in PiGear Nano, even within the case.
It has a dedicated opening for the antenna connector, so you can still connect external antenna to your CM4.
It comes with four M2.5 screws and a silicone thermal pad. You can put the silicone thermal pad between the metal shield of the SoC and the heatsink, to improve the thermal conductivity.