We no longer carry this product. We found our less expensive blue aluminium heatsinks to be just as good.
This is a shiny forged copper heatsink made by Enzotech, small enough to fit on a stepper driver. It is supplied with double-side 3M thermal adhesive tape.
This is the ideal heatsink for mounting on top of A4988 drivers. With our tall replacement pin headers, there is just enough room to mount this heatsink on the underside of the driver carrier board too, where it will do the best job of removing heat from the driver chip (thermal resistance almost an order of magnitude lower than the top of the chip). This works especially well with the black and purple Pololu drivers.
Dimensions: 6.5 mm square, 14.1 mm tall.