Leviton Socket with Outlets, White R52-01403-00W - The Home Depot
10 Pack Lamp Socket Changer Medium Edison Base Socket - 12VMonster Lighting
CliCli E26 Standard Medium Base Light Bulb Socket Extender (Extension: 3 CM/1.18 Inch), E26 to E26 Socket Extension Adapter, Max 60W and 160℃ Heat-Resistant Medium E26 Screw Base Adapter (6-Pack) - - Amazon.com
9 Pack E26 E27 Lamp Socket with Shade Ring,Light Bulb Socket Holder Screw in Standard Base Medium Edison Retro Pendant Bulb,Basic Black Replacement Hold Light Cage Cover - - Amazon.com
Platinum E26 Medium Screw Socket Extender Male to Female – BulbAmerica