Review on 🔥 Easycargo 12 Pack TO-220 Heatsink + Insulator/Mounting Kits for LM317 LM317t L7805 L7812 L78XX Voltage Regulator, IRF Z44N 3205 520N 630 1404 MOSFET Transistor - Silver 20mm x 15mm x 10mm (12 Pack) by Ron Turner

I use them to cool some PWM FETs on a hobby board. They lowered the temperature from "burn fingers" to "too hot to hold." With a little cross ventilation they are just warm. The threaded screw hole is comfortable to the touch and eliminates the hassle of fumbling with a nut on the back. These are not large heatsinks and do not solve serious overheating problems. But they do what they're supposed to do. Unfortunately, there is no information in Celsius/Watt for either tRca or heat output. Look elsewhere for specs or use trial and error.