Aftermarket Mercury Mariner replacement keys: 17 in-stock listings for model years 2005–2011, including key fobs, from $21.60. Common FCC IDs: CWTWB1U793, CWTWB1U331. Match the FCC ID and part number on your current key, or use our free VIN lookup. Keys are not OEM and most need cutting or programming; eligible items can be returned within 90 days.