Vodafone launched its 4G network in London at the end of August, and has recently expanded it to Birmingham, Coventry, Leicester, Nottingham and Sheffield. (It'll also come to Glasgow, Liverpool and Manchester by the end of October.)
This little doohicky is 4G-ready, so will bring blazingly fast browsing and download speeds to any device with a Wi-Fi connection. As long as you're in an area with coverage, that is.
It's pretty compact, with about the same footprint as an iPod Touch, so it fits easily in your pocket.
Having said that, it's fatter than any smartphone we've seen recently. And given that mobiles pack in a lot more processing than this device, and they manage to be pretty svelte, it's a shame Vodafone couldn't find a way to slim it down.
Setting it up is a cinch. Slide in the SIM card, turn it on, and it'll automatically connect to the network. It only takes a few seconds to start up.
You then need to switch on Wi-Fi on your device, and the R212 will appear as one of the options. Click it, enter the password that's printed on the back (or you can double tap the power button to show it on the screen), and you're hooked up.
You can connect up to 10 devices at once. If you don't want to enter a password, holding the WPS button for five seconds will open up the network as if it was unprotected, so you can jump straight on.
It's handy if a few of you want to get online. But beware that during the set-up process anyone nearby could hijack your network and start rinsing your data allowance, so be wary.
Browsing speeds are excellent, with most web pages loading in under a second. Even video-heavy sites like YouTube took only a couple of seconds to load.
Videos on YouTube and Vimeo were quick to start and judder-free. According to the Speedtest.net app, we scored a 12.35Mbps download speed, and 14.37Mbps upload.
As an indicator of how fast that is, a 12MB app took about four seconds to download.
Pointing your browser at http://vodafonemobile.wifi brings up the configuration screen, with specs like speed, battery life, how long you've been connected for, and the signal strength.
Or you can download the accompanying app, Wi-Fi Monitor, which is free on iOS and Android. Again, it shows the same specs as the web page, though not speeds, which is a bit of an oversight.
The lightning-fast speed is a double-edged sword, though.
By browsing, watching a couple of videos, downloading a couple of apps and updating some others, we easily chomped through 500MB of data in a couple of hours. Add in a couple of movie-length videos, and we got through nearly 2GB in a single day.
Obviously most people will use the R212 when they're out and about, and probably won't be using it as intensively as in our test.
But still, data plans only go up to 10GB and prices start at £10 a month for 1GB, so you could find yourself maxing out before too long if you're not careful.
One other slight niggle. The power button isn't that responsive, so you have to be pretty firm to register your press. But the upside is it's less likely to be pressed accidentally in your pocket.
There's a micro-SD card slot too, so you can access your files quickly over a wireless connection. And the battery life was pretty good as well.
We left it on for 24 hours, and only got down to 50 per cent gone, so it should last you a couple of days before needing a recharge.
Overall, the R212 is a very handy device. It's well-built, reliable, and does everything you need it to do.
If you need a speedy connection when out and about, and you're in an area with 4G coverage, it could well be a lifesaver.
Find out more about the Vodafone 4G ready dongle here: Vodafone 4G Mobile Wi-Fi