Lamp, Identification, Downward, Type C. Stores reference 5C/557. Bakelite cased lamp, approximately 13cm diameter x 8cm deep. This example is fitted with an original bulb and has a red tinted glass lens (other colours were used) and short wiring loom. These lamps were used on many aircraft including Spitfires and Mosquitos. Three were used in different patterns primarily to identify friendly aircraft at night. Stock code M26427.