They look a bit like wall mounted flat screen tv's. Someone suggested them as the best/most economical form of heating for a property not on the gas grid.
I think they could be right, but most economical is a tough one, as in a 1850s flat would "want" heating ~5-6+ months a year but a 2012 build 5-6 days per year
Like in the 1940s!, my neighbour says his will heat a room real good in 10mins, but attached to a wall id expect major markings (black shadows)