Fischer elektronik heat sinks 29 x 11m w x h fischer elektronik sk 09 50 sa the fischer elektronik 72 heat sink sk 09 50 sa has been specially developed for power transistors with an extruded design the effective heat dissipation makes it ideal for a wide range of applications fischer elektronik sk 09 50 sa cool rail 29 x 115 x 50mm heat sink 72cw