These are one piece extruded aluminum heat sinks
that were recovered from industrial motor drives. They have internal
slots for PCB mounting so originally they served as both the product
housing and the heat sink for seven power devices. With some creative
imagination you may be able to use this feature in your design for a
unique and distinctive looking project. The red color is the anodized aluminum finish and not simply paint, so it is very durable. They measure 4.25” L x
4.75” W x 3.5” H and weigh 1.5 pounds each. The PCB slot holds a
board 0.060” thick and up to 4.25” x 3.25”. They have 7 holes
in the walls, 4 tapped holes in the base, 2 tapped holes in one end,
and 6 slots on the mounting flanges. Thermally, I would estimate each
heat sink would easily handle a 150W AB amplifier channel. These are
in very good condition with just a few small scratches and have been
cleaned free of thermal grease. Buyer to pay FedEx ground shipping on
the 4 pound box. Thanks.