FUL BLACK LIGHT (BLB) - The Sunlite 40 watt blacklight bulb (BLB) emits ultraviolet (UV-A) light at 365nm wavelength perfect for lighting up reactive surfaces while not illuminating the surrounding areas. GX10q 4-Pin Base GX10Q BASE - 4-Pin GX10q base for use in many residential and commercial fixtures both indoors and outdoors. Outdoor use requires a weather protected fixtures. FESTIVE LIGHTING - Ideal for creating a glow effect with colors like true white and neon hues for parties, clubs, and Halloween decorations. With a 5,000 hour life span these bulbs will last up to 4.6 year (based on 3hr/day use) VERIFY AND DETECT - Also great for verifying security features on ID cards and currency. Also use to detect pet stains on carpets or furniture that are not otherwise visible to the naked eye. VARIETY OF USES - Designed to work with a variety of indoor and outdoor fixtures in both residential and commercial applications. Flowtron replacement bulb. Sold by a USA Based Company