This is the OSRAM SYLVANIA FEV 200w 120v BA15d Double Contact Bayonet base Halogen light Bulb Osram 54441, or “FEV lamp”, has most common uses in stage & studio applications. It has many uses in any operating position and features superior color rendering to cast whatever is illuminating in the optimal light. The “FEV lamp” can be used in stage & studio fixtures that use appropriate wattage, voltage, and are compatible with BA15d Double Contact Bayonet bases.