A luminaire includes a heat spreader, a heat sink, a light source and an outer optic. The heat sink is substantially ring-shaped and is disposed around and in thermal communication with an outer periphery of the heat spreader. The light source is disposed in thermal communication with the heat spreader, the light source having a plurality of light emitting diodes (LEDs) that are disposed in thermal communication with the heat spreader. The outer optic is disposed in optical communication with the plurality of LEDs. The heat spreader, the heat sink and the outer optic, in combination, have an overall height H and an overall outside dimension D such that the ratio of H/D is so dimensioned as to: cover an opening defined by a nominally sized four-inch can light fixture; and, cover an opening defined by a nominally sized four-inch electrical junction box.