# Carrier filtering
You can filter carriers based on the module fields.
For this to work, you need to use the following standard names for your fields:
width
height
depth
Then the module will pass the values of these fields to PrestaShop so that it can filter the carriers correctly.
These standard names will only work if your fields units are the same as the Dimension unit
that is configured in the Localization
page
If the field unit is millimeters
then you can suffix the field name with _mm
width_mm
height_mm
depth_mm
If the field unit is meters
then you can suffix the field name with _m
width_m
height_m
depth_m
The module will detect these suffixes and will convert the values to cm
before passing them to PrestaShop