6-String Guitar String Adapter – Peter Weiss Designs
Amazon.com: BTF-LIGHTING AC100-240V to DC5V8A Max40W Suit 7A 6A 5A 4A 3A 2A 1A Device Transformer Power Adapter Converter with 5.5x2.5mm DC Output Jack for WS2812B WS2811 WS2813 SK6812 etc LED Strip/String :
GU24 to Male IDEAL Socket String Adapter – BulbAmerica
Steinberger Guitars STADB05 Adapter 5-string BK – Thomann United States