This is the most unusual Wi-Fi adapter I have ever seen.

Shaped like a sphere, the D-Link AC1900 Wi-Fi USB adapter looks nothing like the normal thumbdrive-shaped models out there. Instead, it looks like the Death Star from the Star Wars movies.

Even better than its novel looks is the fact that this is the fastest USB-based Wi-Fi adapter in the market.

It supports the latest Wi-Fi 802.11ac standard, which provides up to a maximum theoretical speed of 1,300Mbps.

This is significantly faster than the 867Mbps supported by the Wi-Fi adapters in new laptops. In fact, its closest competitors would be Wi-Fi adapters built for desktop PCs.

Everything looks neat with this product. Its antennas are hidden within the spherical body. A Wi-Fi Protected Setup button lets you quickly and securely connect the D-Link to a compatible router.

A blue LED along its circumference acts as a status indicator - a solid light means everything is working fine, while a blinking light indicates a problem.

Since it uses the USB interface, the D-Link is a convenient tool to bring an older laptop that is using a slower Wi-Fi standard up to date with the latest Wi-Fi technology. But for the best Wi-Fi speeds, the D-Link should be connected to a USB 3.0 port.

To test its speed, I used a home network powered by a Netgear AC1900 router and two laptops. One laptop was connected to the router via Ethernet while the other was connected via Wi-Fi using the D-Link.

The result: the D-Link managed an average download speed of 615Mbps. This is slower than what I had anticipated, given its specs.

As a comparison, my laptop's integrated Wi-Fi adapter delivered 522Mbps. So the D-Link would make a modest upgrade.

Nonetheless, it is still the fastest USB Wi-Fi adapter I have tested.

Vincent Chang

• The fastest Wi-Fi USB adapter you can buy now, the D-Link is useful to upgrade an ageing device to the latest Wi-Fi speeds.