Kenmores have different needle and presser foot systems. Some have a "left homing" needle, some have a "super-high shank," some use a standard low shank, some have the 5 mm hole in the needle plate, some have one that's a little wider (maybe 8-9 mm). Most rulers and tape measures have centimeter marks on them. There are 10 centimeters in a millimeter.
The walking foot you need depends on which model you have. If you have a super-high shank, I understand there is an adapter to allow it to use a standard low shank foot.