The top and bottom 140mm NF-P14 fans spin at 1200-750RPM but it's best to keep the speeds matched. Two 3-pin motherboard headers provide power, neither fan is PWM compliant. Looking at the top of the Noctua NH-C14 heatsink with the fans removed you can see two small open squares about half way up the fins stack - these are for the screwdriver to pass through when installing the heatsink. The aluminum fin stack is 140x137mm in size.

The Noctua NH-C14 heatsink stands 130mm tall, the bulk of it elevated 66mm over the CPU socket for clearance (37mm including the bottom fan). The six 6mm diameter copper heat pipes pass through the 140x38mm aluminum fins in an asymmetrical pattern. Each nickel plated aluminum fin measures 0.4mm thick and is spaced 1.5mm apart. Note the wire fan clips securing the two fans. A portion of the fin edges are given a saw-toothed profile.

The nickel plated copper base plate measures 40x38mm in size. The copper base plate is 2mm to 5mm thick. The six 6mm diameter copper heatpipes are soldered to copper base plate and aluminum fins along their entire length. A steel support column (center) helps protect the heatpipes from bending under the weight of the upper portion of this 1000 gram heatsink.