How to match MultiSelectCustomFieldRef to CustomList?

We have a custom select field for the size of an item.

I can't figure out how to match the MultiSelectCustomFieldRef
I get from an item back to the CustomList so I can get
the name of the size selected for the item.

Before processing the items, I am getting the custom
lists from Netsuite using this code:

CustomizationType cType = new CustomizationType();
cType.setGetCustomizationType(GetCustomizationType .customList);
GetCustomizationResult gcr = NetsuiteUtil.getInstance().getCustomization(cType) ;
for (int i=0; i<gcr.getRecordList().getRecord().length; i++) {
CustomList cl = (CustomList)gcr.getRecordList().getRecord()[i];

The cl.getInternalId() gives me integer values like 1,2,3, etc.
If I use cl.getName(), I get the display name of the list, such