PH-Hat Wall Lamp from Louis Poulsen. A wall lamp that gives an indirect and completely dazzle-free light. The light diffraction depends on the angle of the screen. The inside of the screen is rose-colored, giving the light a warm tone. With PH-Hatt, Poul Henningsen wanted to create a lamp for bedside lighting, but also suitable for foyers, stairwells and corridors.