GE Lighting 81590 50/100/150-Watt A21 3-Way Light Bulb, Halogen
GE 81590 50/100/150-Watt A21 3-Way Edison Halogen-Bulb:  A21, Base:  3 Contact Medium Screw (E26D), Voltage:  120, Rated Life  2500 hours, Primary Application  3-Way