Amazon.com: Besmelody 10-Pack DC Power Converter Plug, 5.5mm x 2.1mm to 3.5mm x 1.35mm Tip Size AC/DC Adapter Barrel Plug Connector for Wall Chargers : Electronics
DC Barrel Plug Adapter to 6.5mm x 4.4mm from 2.1 x 5.5mm | AC-DC PowerShack
U.S. to METRIC- Barrel Adapter Thread Converter U.S. 5/8″ x 24 (female) to M15 x 1 RH (male) – SKU#088 – Hughes Precision LLC