The Can Converter 4-in Remodel or New Construction Non-ic Open Recessed Light Kit in the Recessed Light Kits department at Lowes.com
Trailer Light Converter
Amazon.com: United Pacific 90620 Trailer Light Converter for Trailers, 5-Wire System to 4-Wire System, 18G Bonded Wire w/Flat 4-Way Female Connector - ONE Unit : Automotive