Bulbrite 40T10BL 40W Halloween Black Light Tubular Bulb Black light provides dramatic special effects, perfect for dorm rooms, parties, Halloween, decorating, clubs, parties, and more Reduced visible light combined with the lamp&rsquo;s natural heat simulates &ldquo;night time&rdquo; in reptile tanks 40 watts, 100 CRI, 500 hour average rated life, Medium (E26) Base Maximum Overall Length is 5 inches; Bulb Diameter is 1.25 inches