When doing replacement or upgrading on 2009 – 2018 Ford Flex with halogen capsule headlamps HID, the bulb size guide is necessary for you to take the reference.
Jump to corresponding car model with the catalog bellow.

High Beam and Low Beam Headlight 2009 – 2018 9008
Front Fog Light 2009 – 2018 H8/H11/H16
Back Up Light 2009 – 2018 921
Brake 2009 – 2018 4057
Dome Light 2009 – 2018 578
Front Side Marker 2009 – 2018 194
Front Turn Signal 2009 – 2018 3457NA
License Plate 2009 – 2018 6418
Parking Light 2009 – 2018 3357NA
Rear Side Marker 2009 – 2018 194
Rear Turn Signal 2009 – 2018 4157
Luggage Compartment 2009 – 2018 578
Glove Box 2009 – 2018 161
Inner Tail Light 2009 – 2018 194
Map Light 2009 – 2018 12961
Outer Tail Light 2009 – 2018 4157
High Beam and Low Beam Headlight 2009 – 2018 D3S
Front Fog Light 2009 – 2018 H8/H11/H16
Back Up Light 2009 – 2018 921
Dome Light 2009 – 2018 578
Front Turn Signal 2009 – 2018 3457NA
License Plate 2009 – 2018 6418
Parking Light 2009 – 2018 3457
Luggage Compartment 2009 – 2018 578
Glove Box 2009 – 2018 161
Map Light 2009 – 2018 12961