Essentially standing on the shoulders of IT giants, the Devolo dLAN 500 WiFi combines two established networking technologies – Wi-Fi and powerline – in a manner that's so obvious, I'm surprised it's not more widespread.

Basically, your £120 buys a package of three boxes that – together – are claimed to 'cure weak Wi-Fi'. One of these boxes, the dLAN 500 Duo, plugs into a spare mains outlet and interfaces with your router via Ethernet. It then communicates at up to 500Mbps, via your mains wiring, with the other devices (called dLAN 500 Wi-Fis). The latter are inserted into mains sockets convenient to where the extra connectivity is needed.

In addition to a 2.4GHz-only Wi-Fi access-point, each gives you a fast Ethernet port that can hardwire a console, Smart TV or other networkable device. Locate each dLAN 500 Wi-Fi sensibly, and you should have full Wi-fi coverage within the home. 

To spare you the bother of having to manually log into different access points every time you shift from room to room, Devolo has built in its 'Wi-Fi Move' technology to automatically synchronise settings between its devices; however, you'll still need to log in separately to the Wi-Fi provided by your router (unless it's turned off). WPS is supported too. The system – passwords, visibility, access times, wireless channels, updates and so on – can be managed via a webpage or the supplied 'Cockpit' Windows software.

Overall, I found this networking accessory worked well, speeds exceeding 300Mbps routinely being reached even over my archaic but extensive mains wiring. With the a Roku 3 media player, BBC iPlayer never skipped a beat even in 720p mode. I also used it to network my mains-wired shed, Wi-Fi ensuring that smartphones and media players could remain reliably connected while pottering in the garden. 

Devolo dLAN 500 Wi-Fi, £120, www.devolo.com/uk

Verdict: 4/5