6pcs 3pairs Fluorescent Cfl 14w 28w T8 To T5 G13 To G5 Tube Light Endcap Lamp Base Holder Socket Converter Adapter - Lamp Bases - AliExpress
E-Simpo® 50-Pack CFL T8 to T5 Fluorescent Tube Side Cap Adapter,T8-T5 Tube Side Cap Converter, Allow You Install T5 28W CFL into T8 Fixture (L31 for 2ft/465mm T5 Tube) - - Amazon.com
T5 to T8 Socket Base LED Adapter Holder Light Bulb Lamp Tube Fitting Converter | eBay
4200000 - adapter Set T5 / T8 powerLED/powerLED+ - EHEIM Service
E-Simpo® 50-Pack CFL T8 to T5 Fluorescent Tube Side Cap Adapter G13 to G5 Tube Socket Adapter T8-T5 Tube Side Cap Converter, Allow You Install T5 28W CFL into T8 Fixture (L36 for 4ft/1165mm T5 Tube)