Fischer elektronik fk 220 sa 220 25 c w heat sink for to 220 to p 3 hous fischer elektronik fk 220 sa 220 the fischer elektronik 25 heat sink is a finger shaped attachable heatsink for semiconductor design to 220 manufactured to a high standard and ideal for transistors with thin bottom thickness 0 5 mm fischer elektronik fk 220 sa 220 25 c w heat sink for to220 and to p 3