Fischer Elektronik Cool Rail 97 x 25 x 50/75/100mm Heat Sinks – Fischer Elektronik SK 72 100 SA, The Fischer Elektronik 1.6° Cool Rail 97 x 25 x 100mm Heat Sink has been specially developed for semiconductor-design TO 3. The effective heat dissipation makes it ideal for a wide range of applications. Fischer Elektronik SK 72 100 SA Cool Rail 97 x 25 x 100mm Heat Sink 1.6°C/W