Rare Ceiling Light with Daylight PH 4 shades.
Opal glass with partially blue tinted interiors, nickel plated metal.
Impressed 'PH-4' with patent number to shade mount.
Henningsen was known to greatly experiment with different shade colours for his PH lamps. One of these was a special 'daylight' shade, used in special circumstances when it was important to be able to distinguish between the colours.