I had the unfortunate experience today of trying to fit a customers 13a double sockets, they were hidden screw type with USB outlets incorporated.. I had no choice but to fit them, if you are thinking of doing so please don’t they are a very badly designed unit they fit into a dual back box with a rizzla smoke paper clearance top and bottom. If the back box is slightly off kilter then there’s no way of levelling these babies up, I’m going to get in touch with ever ready and see what they say about it