3 Mobile's Wi-Fi Router allows a single mobile broadband connection to be shared by up to four users. This convenient device is well designed and compact, but it only works with 3 Mobile broadband accounts.

The D100 certainly scores some points for its design. Available in either black or white colour schemes, the modem has a retro feel. Its gloss white and silver body not only looks the part but feels reasonably sturdy as well. Conveniently, when 3's USB modem is plugged in, it can be concealed behind the sides of the modem thanks to a rotatable USB port, preserving the stylish look. Our only complaint with the design is the lack of a stand: the D100 stands upright well enough, but it is easily knocked or bumped onto its side.

The Wi-Fi router requires an included AC adapter to function, so it's meant for the home or office environment, and not as a mobile solution. The idea is that you can use it to share a single mobile broadband connection, with 3 recommending the unit be used by "two to four people at a time". 3 also states that speed will reduce when users are downloading concurrently. This is definitely true, but for a couple of users who just want general Web browsing, the D100 does a reasonable job.

Set up is as simple as plugging the unit into power and inserting the USB modem. For wireless users, it's then just a matter of searching for a wireless Internet connection and entering the WPA password, conveniently located on a sticker at the bottom of the D100. If you'd prefer a wired connection, an Ethernet port at the rear of the modem allows the unit to be connected to a LAN port on your PC.

Performance is a mixed bag. It is important to note that there are many variables to consider when assessing the performance of mobile broadband products, including coverage area. We tested the D100 in our North Sydney offices. Despite the speeds becoming painfully slow when three or more people were downloading concurrently, it's fine for general Web browsing with multiple users. Using Speedtest, the download and upload speeds were the same when using the D100 and when we plugged 3's USB modem directly into our PC — about 1600 kilobits per second on both accounts.

Where the D100 obviously suffers is concurrent downloads. As 3 suggests, downloading simultaneously slows speeds significantly. As an example, downloading iTunes (a 57MB file) with the USB modem directly plugged into our PC, we managed to achieve speeds of up to 180 kilobytes per second (KBps). Using the D100, peak speeds dropped slightly to 168Kps, while three users downloading the file with the D100 resulted in speeds ranging from just 28KBps to 80KBps. Concurrent Internet browsing is fine, but if you've got a household full of heavy users, then this isn't the device for you.