The NH-D14 is comprised of six nickel-plated copper heatpipes designed to transfer heat from the base of the heatsink up and into the aluminum tower fins for dissipation. Both towers come in contact with all six heatpipes for even heat distribution.
The base of the heatsink is copper with a nickel plating, presumably to prevent oxidation / discoloration. Bare copper looks great at first but after being exposed for a while, it begins to tarnish and isn't very pretty. Of course this wouldn't apply to the base of the heatsink since it wouldn't be exposed, but perhaps Noctua simply wanted to go for a uniform look. Anyway, the base is nice and smooth but not overly shiny as you can see in the reflection test above.
Here we have a closer look at the fans and their mounting system. Notice that Noctua uses translucent rubber strips to reduce fan vibration against the aluminum fins.
The fans are classic Noctua, with a cream colored casing and brownish-orange fan blades. Some users may not particularly care for this color scheme and can opt to swap out the fans for solid black or LED-embedded fans to better match their interior case theme. These fans look fine to me so I will stick with them. Both fans have 3-pin headers with the cables covered in black mesh. Noctua also includes a pair of Ultra Low Noise Adapters (U.L.N.A) that reduce fan speeds from 1200 / 1300 RPM to 900 / 900 RPM on the 140mm and 120mm fans, respectively.
Finally, note that the fan blades have a unique zig-zag pattern cut into the blade edges. Noctua calls these Vortex-Control Notches. "The two Vortex-Control Notches at the trailing edge of each blade make the flows along the suction and pressure side mix more smoothly, allowing for less turbulence and velocity loss, which leads to increased efficiency as well as a significant reduction in noise emission." If you look closely you will notice that these notches are staggered and not in the same place on every blade.
Here we have a look at the heatsink sans fans. You are required to remove at least the middle fan in order to install the unit.
Speaking of installation, let's move ahead and check it out.