Fischer elektronik cool rail 180 x 48mm w x h heat sinks fischer elektronik sk 53 100 sa the fischer elektronik 065 cool rail 180 x 48 x 100mm heat sink has 2 x to 3 2 x cb drilling pattern with effective heat dissipation making it ideal for a wide range of applications fischer elektronik sk 53 100 sa cool rail 180 x 48 x 100mm heat sink 065cw