Philips 13-Watt 21 in. Linear T5 Fluorescent Tube Light Bulb Cool White (4100K) 546499 - The Home Depot
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
Satco S2911 13w T5 F13T5/D Daylight 21 inch Preheat Fluorescent Tube L – BulbAmerica