US Lamp Socket Adapter E 27 to E40 Lamp Base Converter E27 to E40 Lamp Socket | eBay
E40 Lamp Holder - Online Hydroponics Shop
E26/E27 to E39/E40 Light Sockets Adapter, Light Bulb Socket, Bulb Base Adapter, Converters Lamp Holder, Converts E39 Pin Base Fixture to E26/E27 Standard Screw-in Socket (Pack of 10)