Fischer Elektronik Heat Sinks for TO-3/TO-55/SOT-9/SOT-32/TO-220 – Fischer Elektronik FK 201 SA-CB, The Fischer Elektronik 25.4mm 6° Heat Sink is a finger shaped heatsink with combi punching designed to a high standard and ideal for power semiconductors. Fischer Elektronik FK 201 SA-CB, 6°C/W Heat Sink For TO3 TO55 SOT9 SOT32 TO220