Computer cooling components Adafruit

clip-on heatsink, 21.5 x 10.2 x 19.2 mm, 1.88 g Get the most out of your regulators, transistors and other TO-220 packaged chips by clipping on a heat-sink. Your transistor or regulator may advertise it can handle high currents but when multiplied by the drop voltage, the Wattage may be too high for the bare chip! Most TO-220's can disipate about 2W's worth without a sink.

This basic, and easy-to-use 23°C/W sink will let you burn about 4 Watts of power through a TO-220 (assuming an ambient temperature of 25°C and max die temp of 150°C). No screws or thermal paste required.