Transistor Spring Clips. Transistor spring clips designed for single point fixing of power transistors such as TO220, TO218, TO247 and TO3P to their heatsinks They provide strong central pressure (max. 7.5kg) to maximise the thermal transfer properties to the heatsink with only one circular hole required for two transistors Suitable for any heatsink panel or pad thickness Zinc plated with clear passivated finish - Isolation voltage 1000V