ZM-NC3000U was made using aluminum and plastic. The aluminum grill with 1300 vents is placed on the top part whereas plastic was used for the rest. The aluminum grill also has a rubber pad that will keep your laptop from sliding. 
The fan is pretty large and is placed in the center beneath the aluminum grill. This means the 220mm fan will do an equally good cooling job on smaller as well as larger laptops. You can regulate fans peed via the wheel on the back (picture below), which we didn’t quite find as practical. The fan’s RPM ranges from 620 to 720 whereas the loudness goes between 17 dBA and 23,5 dBA. 
The fan can be turned off via the power button. The ZM-NC3000U can be powered via your laptop’s USB port but you can also choose to power it directly from the 5V connector. If you find your laptop to lack enough USB ports, then you’re in luck as the ZM-NC3000U acts as a USB 2.0 hub with three ports. 
Zalman ships the USB/power cable with the device. If however you are using all USB ports at the same time, it is advised to use external adapter which unfortunately does not come in the package.
ZM-NC3000U is made to keep your laptop at a slight angle. Of course, the angle can be adjusted the way you see fit via small feet similar to those found on keyboards. 