AMATRON ETL Listed 16" T9 24W LED Circline Bulb LED Circular Tube 5000K Daylight Frosted Lens with Non-Dimmable External Power Driver to Replace 16 inch 40W Fluorescent Circline - Led Household Light
Norman Lamps FC16T9-CW - 40W, 2,590 Lumens, 1.13 in. Tube Diameter - Fluorescent Bulbs - Amazon.com