G4 to E27 Socket Base Halogen LED CFL Light Screw Bulb Adapter Converter Holder | eBay
Amazon.com: HP EliteDisplay E27 G4 27 Inch IPS FHD Multi-Device Monitor Bundle with Blue Light Filter, HDMI, DisplayPort, HDMI to USB-C Adapter, Compatible with MacBook, MacBook Pro, MacBook Air, iPad and iPhone :
E-Simpo 10PCS E26 to Gu5.3/GU4/G4/MR16 Adapter- Standard E26/E27 Edison Screw Base to MR16 GU5.3 G4 Gu4 Base Adapter Holder Converter (PBT Material) - Amazon.com
E-Simpo 10pcs E26/E27 to MR16/Gu5.3/G4/Gu4 - Standard E26/E27 Edison Screw Base to MR16 GU5.3 G4 GU4 Base Adapter Holder Converter (Ceramic Material) - Amazon.com
Papaba E27 to MR16 Bulb Socket,E27 to G4/MR16/G5.3 LED Light Bulb Socket Base Lamp Holder Adapter Converter - Walmart.com
LLB-44EE-01-00 E26 to G4/MR16 Adapter by LunaSea
ARSMI E27 to G4 GU5.3 MR16 Adapter E26 to MR16 LED Light Bulb Extend Plug Lamp Holder Converter Power Adapter Base Socket Lamp Holder Converter - Amazon.com
Source adapter e27 to g4 lamp socket e27 to mr16 on m.alibaba.com