690 Extruded Heat Sinks for TO Devices with Clip Wakefield-Vette 690 Extruded Heat Sinks for TO devices with Clip are heat sinks designed for TO-126, TO-220, and TO-247 devices. These Wakefield-Vette aluminum extruded heat sinks offer an integrated, robust holding feature. The 690 series heat sinks provide a solderable retaining pin for PCB mounting and feature optimal heat transfer between the component and the heat sink.