Yegren 8w 10w Fluorescent Ring Lamp Tube Inner Diameter 67.5 Mm 70 Mm 78 Mm Microscope Top Ring Light Source Inner Core - Microscope Parts & Accessories - AliExpress
Large Replacement Fluorescent Tube Ring Light Bulb for Diva CFL 18"
GE Warm White 4-pin Circline Fluorescent Light Bulb in the Tube Light Bulbs department at Lowes.com
Amazon.com : Neewer 18 inches Collapsible Photography Video Light Softbox Diffuser for 75W(600W Equivalent) Ring Fluorescent Light Flash Light : Electronics