BestKeys 2004 Mercury Mountaineer 3 Button Replacement Keyless Entry Remote Key Fob We will provide a link to our website with Free Do-It-Yourself programming instructions with your order. Remote requires 1 working key to program. Save up to 70% off dealership prices Lock + Unlock + Panic YOUR KEY SUPPLIER is the only authorized seller of BESTKEYS products. All warranties will be voided if bought from any other sellers.