Review on Easycargo Raspberry Pi 4 Heatsink Kit (Pack of 20) - Aluminum & Copper with 3M 8810 Thermal Conductive Adhesive Tape for Enhanced Cooling of Raspberry Pi 4 B & Raspberry Pi 3 B+ by Jacob Mayberry

The pads and fins stick firmly to the surface. It dissipates heat well without burning the glue used to glue it, which is definitely an important consideration for any radiator. The copper pads are useless on the Pi 4 as the design is different. So don't expect them to come in handy if you only buy these for the 4b model. Combine them with an actively cooling GPIO fan and you get the best cooling you can get for your small pocket computer.