I know a lot more about electronics than electrical installations but I consider that MK make good / safe 13a sockets. I have no idea whether they properly understand the issues surrounding AC adapters or whether who they've contracted does. Safety is relative as nothing can be completely safe in all circumstances but I am still against the idea of a mains / usb power supply which cannot be disconnected without switching off the entire ring main for the reasons I've previously stated. USB has the added safety issue that if the DC does go live it is very likely that a person plugging in a USB cable will at some point touch the metal connector. I know this applies for all USB adapters but I genuinely believe it's more of an issue when we have devices which cannot be disconnected (and in many cases are of unknown quality).
A scenario would be that you have one of these fitted, you use it for 3 years and then you stop using it because it's started to fail and the touchscreen of your phone stops responding properly when you plug in the cable (a common symptom of a failing supply). A year later when you're out of the house the capacitor has built up pressure and blows covering the inside of the circuit with debris. You don't know because you were out of the house. The debris bridges between the mains / low voltage on the circuit. The USB is now live but you don't know because you don't use it. Someone comes into your house and plugs in their phone to charge it unaware that the USB is faulty.
Had it been an issue with a normal adapter you would have stopped using it / thrown it away and the situation would never have occurred.

These would only trip the power if the fault either caused the ring to consume more than the rating for the ring, or if they leaked current to earth. Neither is very likely to happen and the second even less so as the USB circuit is unlikely to even have an earth connection. The most likely fault and one that will certainly happen in time is that the capacitor(s) will go bad. This initially will cause the output to become unstable so you will stop using the device as it no longer charges properly. Then the situation will keep getting worse until it either goes open circuit, blows, explodes or catches fire. Faults can also cause mains voltage to appear on the USB output which is dangerous enough but usually mitigated by the fact that you would have stopped using the faulty device at the first sign of problems. Here though, it will still be connected.
Do you believe that this is anything but a cheap unbranded adaptor?

Good find OP. Bought 2 last week from Toolstaion and they were £11 each. They had a 2.4A and 1.2A output on each. 2.1A USB output is fine to charge the IPAD so good price.

Thanks,I have been thinking of buying some of these recently and at this price i thought i`d order a couple.

Good find. If you only need one Screwfix have very similar for £6.99. Bought one yesterday.

I think everything is 15% off at Wickes Friday 25th March to Mon 28th March.

good find op, heat added

So the usb ports are 1a each. Almost useless.

Good price but read all the previous threads on these kinds of things to see why you shouldn't bother.

Are these mounted into the wall or externally placed?