Plug & Play 16 Inch T9 Circline LED Bulb Ballast Required!
lumenivo 40W Circline Replacement Bulb 2CT6 Bulb 2800K Circline Fluorescent Lamp Bulb - Double Circle Light Bulb with G10Q-4 4 Pin Base in a Square - 1 Pack - Amazon.com
Feit Electric 20-Watt 12 in. T9 G10q Type A Plug and Play Linear Circline LED Tube Light Bulb, Daylight Deluxe 6500K (4-Pack) FC12/865/LED/4 - The Home Depot