The Norman Lamps F20T12-BL is a 20W T12 black light fluorescent tube designed to emit ultraviolet energy centered at 350nm, within the UV-A spectrum. The white-glass envelope construction of this Black Light (White) type allows the tube to produce both its characteristic UV output and a visible glow, distinguishing it from the darker-glass BLB variant. The lamp measures 24.0 inches in length and 1.50 inches in diameter, fitting standard G13 medium bi-pin fixtures used across a wide range of T12 fluorescent applications. Rated at 15,000 life hours, this fluorescent tube offers a long service life well-suited to installations that require consistent and reliable UV-A output over extended periods. The 350nm UV-A emission makes this T12 fluorescent lamp effective for a broad range of uses including UV inspection, leak detection, forensic analysis, entomological (insect) traps, event and theatrical accent lighting, and decorative blacklight displays. It serves as a direct cross-reference replacement for the Sylvania F20T12/350BL and is also noted as a replacement for the GT-220 insect lamp. The lamp operates on standard ballasts compatible with 20W T12 preheat-start fluorescent circuits.

• 20W T12 Black Light (White) fluorescent tube, 24.0 in. length, 1.50 in. diameter — fits G13 medium bi-pin fixtures
• Emits 350nm UV-A black light energy for inspection, leak detection, insect traps, and decorative or theatrical blacklight applications
• Rated 15,000 life hours for long-lasting, dependable UV-A output in continuous or frequent-use installations
• White-glass envelope construction produces visible glow alongside UV emission — differentiates from dark-glass BLB type
• Direct cross-reference replacement for Sylvania F20T12/350BL and GT-220 insect lamp