ALUCSET 3 Pack Medium Screw Base to Medium Base Light Bulb Socket Porcelain Extender, E26 E27 to E26 E27 Lamp Bulb Socket Extension Adapter, (Set of 3, Porcelain E26 Extender): Amazon.com: Tools
Noonkey Light Socket Splitter Adapter 2 in 1, Light Socket Extender 360 Degree Adjustable, 9.5 Inch Extension Adapter, 2 E26 Base Bulbs in 1 Socket Y-Shape Holder Converter, PBT Fireproof Material - Amazon.com
ABI 6.5-Inch Flexible Socket Extender for Standard US Light Bulbs - Amazon.com