The Coolermaster Gemin II M4 heatsink measures just 61mm tall, from the base of its exposed copper heatpipes to the tippy tip of its translucent vaneaxial fan. How does manage to squeeze in a fan and enough cooling surface area in a package so thin? Easy, instead of a 25mm thick stock 120mm fan, Coolermaster uses a 13-bladed fan that's just 15mm thick.
When it comes to finding a good low profile heatsink for a compact computer system, HTPC or MediaPC, height is only half the equation. Noise output is usually high on the list, closely followed by thermal performance. Coolermaster make good on most of these points with the Gemin II M4, though the heatsink is really best suited to sub-95W TDP chips as you'll shortly see. The Gemin II M4 heatsink will handle heat loads up to 150W TDP, but only at full fan speed where noise levels are quiet-to-audible. Then again, it's not like you have much choice in sub 75mm tall heatsinks - if you find yourself stuck on super low thermals, super quiet noise levels and a very compact height restrictions, you may find the Gemin II M4 heatsink the ideal compromise.