Incandescent Bulb, Bulb Base Type Single Contact Bayonet (BA15s), Bulb Housing Glass, Bulb Shape S8, Bulb Finish Clear, Color Rendering Index 100, Color Temperature 2767K, Lumens 452 lm, Light Technology Incandescent, Shatter- No, Trade Number 7511 (P21W 24V), Voltage 24V AC, Watts 21 W, Bulb Beam Angle Not Applicable, Rated Life 150 hr, Dimmable No, For Enclosed Fixtures No, Three-Way No, Light Color White, Indoor/Outdoor Usage Indoor Only, Overall Length 2 3/32 in