Satco 80/2134 Intermediate To Medium E17 - E26 Reducer; 1" Overall Extension; 75W; 120V
CliCli E17 to E26 Bulb Adapter (E26 Bulb in Smaller E17 Socket), Intermediate E17 to Standard Medium E26 Screw Base Socket Converter, Intermediate E17 Base Light Adapter of 2 Pack - - Amazon.com
2pcs E17 to E26 Lamp Socket Adapter Intermediate E17 Socket to Standard E26 Socket Converter LED Light Bulb Converters Changer| | - AliExpress
SYLVANIA Lumalux High Pressure Sodium Lamp E17 50 Watt 52 Volts E26 Medium for sale online | eBay
E17 to E26 Light Bulb Socket Base Adapter Converter - Converts Intermediate Socket (E17) to Medium Socket (E26/E27) (Pack of 2) - - Amazon.com