4PCS Heat Sink Kit 40x40x20mm Aluminium Heatsink Cooler 40mm for Cooling VRM GPU Stepper Driver 3D Printers Stepper Motor NEMA 17, TEC1-12706 Thermoelectric Peltier Led

The extrusion is smooth and with a high aspect ratio. The base plate is decently flat and the base material is tick enough to thread a screw hole into.

Well made words as expected

These have very nice thermal transfer. They seem to be of pure aluminum, because they work better than a similar shape and fin style heatsink of 40% larger area and mass. Easy to drill and machine.

used with thermal epoxy to shape to my needs

WiFiルーター子機が過熱するので、貼り付けてみました。ヒートシンクが暖まっているので、効いていると思います。