Fischer elektronik m4 din rail heat sinks for load relay fischer elektronik sk89 75kl ssr1 the fischer elektronik 1 2 din rail heat sink is mountable on din rail 35mm in accordance with din en 50 022 rail material thickness of 1 2 3mm with drillings m4 for relay assembly the effective heat dissipation make it ideal for a wide range of applications fischer elektronik sk89 75kl ssr1 1 2 c w m4 din rail heat sink for relay