The FRITZ!WLAN Stick AC 860 is a USB WiFI dongle that connects your computers or notebooks with any wireless router and provides ideal data transmission with speeds up to 866 Mbit/s with routers that support the Wireless AC standard.
As you would expect this is a pretty basic product, it is a relatively small USB dongle, around the same size as most USB memory sticks. When you insert it into your laptop Windows should auto-install it giving you a new wireless device to use.
Once everything is installed you can select Wifi networks as you would do normally.
Performance is excellent, with the speed depending on how close you are to the router. I was able to achieve transfer speeds of over 700Mbit/s or over 85MB/s when in the same room as the router, with speeds dropping off sharply with the more walls I put in between me and the router.
Overall this is a handy little device if you have an older laptop but a newer router with 802.11ac.
I was unable to find a reputable supplier in the UK that I have heard of that is selling one of this sticks. But Amazon.de is selling them for EUR 42.89 which should work out at just over £30.