24 Light Bulbs - Industrial Performance F32T8/BLB - 32 Watt - 48" Length, 1" Diameter - Bi-Pin (G13 Base) - Black Light Blue Light Bulb -Can replace GE 72760 F32T8/BLB and Norman Lamps F32T8-BLB. Black light blue fluorescent bulbs are designed with a special filter glass that absorbs most of the visible light and has a violet/purple-like hue. This creates a glowing effect when directed at certain materials. Use everywhere you want to create a visually dramatic atmosphere.