Master-Bilt 02-71290 BULB HOLDER W/SPRING , FOR BGF | Parts Town
Leviton 660-Watt Keyless Twin-Socket Lamp Holder Adapter R52-00128-00W - The Home Depot
GX23 To E27/E26 LED Light Sockets Adapter, Light Bulb Socket, Bulb Base Adapter, Converters Lamp Holder (Pack of 1): Amazon.com: Tools & Home Improvement