Any place that sells Motorcraft oil filters will have an application chart showing you which one fits your Focus.
Ranger 2.3 (it fits and works weel, but the original is the FL1) Focus Many other.
Motorcraft ( FL820S ) according to motorcraft . com
Motorcraft ( FL-820-S ) engine oil filter
Fl-1A
This oil filter fits many Ford, Lincoln and Mercury car and truck applications.
( Motorcraft FL-820-S engine oil filter ) for the 4.0 liter V6 and the 4.6 liter V8 engines according to the 2010 Mercury Mountaineer Owner Guide and fordparts.com
According to the 1998 Ford Expedition Owner Guide : For the 4.6 and 5.4 liter V8 engines : ( Motorcraft FL-820-S engine oil filter )
The Motorcraft FL-1A engine oil filter fits NUMEROUS Ford engines ( and also some of the other manufacturers engines )
This is a FRAM air filter. It fits a Ford Focus but I can't remember what year or CC.
Do not install a Supertech filter on your Ford. Install a quality filter such as Purolator, Wix, or Motorcraft. The filter is too important to go cheap. Change your oil/filter every 5,000 miles.
Anyplace that sells filters will have an application chart and can tell you the correct size in any brand of quality filter such as Purolator, Bosch, Wix, or Motorcraft.
For a 2000 Mercury Mountaineer : According to the Owner Guide and fordparts.com : For the 4.0 liter SOHC V6 engine ( Motorcraft FL-1A ) For the 5.0 liter V8 engine ( Motorcraft FL-820-S )