Pool/Spa Part – Hayward – Conversion Kit NA to Propane UHSLN – FDXLCNK0001. Hayward Conversion Kit NA to Propane UHSLN (FDXLCNK0001). Hayward Pool Products Inc. Catalog Part Number: 6223-583. View more great items! This listing is currently undergoing maintenance, we apologise for any inconvenience caused.