SYLVANIA 40-Watt A15 -White- Ceiling Fan Bulbs - Intermdiate Base 12-Pack X22078 Vibration-resistant filaments will not fatigue easily from fan spinning or activity above Intermediate Size Bulb Base, These bulbs are Intermediate base, NOT Medium Base, and NOT chandelier base. Please double check your fixture before purchase Operate In Horiztonal, Vertical, And Angeled Positions Approx. 1,000 Hours Total Life Includes 12 (one dozen) A15 Soft White Ceiling Fan Bulbs