E-Simpo CFL T8 to T5 G13 to G5 Fluorescent Tube Side Cap Adapter T8-T5 Tube Side Cap Converter, Allow You Install T5 28W CFL into T8 Fixture (12-Pack): Amazon.com: Tools & Home
Aluminum and PC Cover High Brightness G13 Base T5 LED Tube Lighting - China LED Tube Light, Integrated LED T5 Tube | Made-in-China.com
Tubi T5 G5 - T8 G13
Feit Electric 32-Watt 4 ft. T5 G13 Type A Plug and Play High Output Linear LED Tube Light Bulb, Selectable White (2-Pack) T548HO/4CCT/LED/2 - The Home Depot