E-Simpo® 6pcs 2G7 4-Pin H Lamp Fluorescent Light Holder 2G7 Base Horiztonal Single Head Tombstone Lamp Socket for LED Fluorescent Tube(2G7) - - Amazon.com
4 Pin G24 to Medium Base - Socket Adapter | CityLightsUSA.com
4 Pin with 2 Meter Lead Wire (18 AWG) - BuyUltraviolet
Bonlux Gx24q to E26/E27 LED Light Sockets Adapter, Gx24 Short 4 Pin to Medium Edison Bulb Base Adapter, 4 Pin CFL Lamp Base Converter, Remove Bypass the Ballast, 10-Pack - Walmart.com
G10Q 4-Pin Tube Light Socket,Ceramics 4-Pin G10Q Base Socket for FC8T9/DL Circline Fluorescent Lamps (Pack of 2) - - Amazon.com