Satco S2911 13w T5 F13T5/D Daylight 21 inch Preheat Fluorescent Tube L – BulbAmerica
F13T5WW – T5 21 Inch Under Counter Fluorescent Bulbs Warm White 3000K 13-Watt F13T5/WW 21” WW Long Life Replacement Tubes for Under Cabinet Lights – Pack of 6 Bulbs - - Amazon.com
Lightwise LWL7W40-F13T5 21" Direct Replacement Led Tube, 7-Watt, White, 4000K, Retrofit 13W T5 Fluorescent Tube of your Uncder-Cabinet Lights 50% Energy Saving, Replace Directly Set of 3 - - Amazon.com
6 Pack of Eiko F13T5/WW 13W Warm White 3000K T-5 G5 Base Lamp Bulb, 6 Pack - Walmart.com
13W 21" T5 Fluorescent Tube White Lamp Series 517mm (ex Pins) Under Cabinet | eBay
Feit Electric 13-Watt 21 in. T5 G5 Linear Fluorescent Tube Light Bulb, Bright White 3000K (1-Bulb) F13T5/WW/RP - The Home Depot