T4 12watt Circular Fluorescent Light Bulb for Desktop Magnifier Lamps, Perfect for precision work, this lamp magnifies and lights up the work surface, Features 3 1/2"" diameter, 3+12-diopter glass lens with 1, 75x magnification, Adjustable lamp head and arm, Removable protective lens cover, Sturdy 4"" x 8"" base, Electronic ballast, UL listed, SKU: ALV14571