Assuming that the list view has objects of the type CustomList as per your code it is displaying the default toString() method of your CutsomList class. You should instead access the variables that you would like to display and toast it.
For example:
public class CustomList {
String title;
public String getTitle(){
return name;
}
}
And in the onClick you can do the following:
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view,final int pos,
final long id) {
CustomList customList= (CustomList )lv.getItemAtPosition(pos);
Toast.makeText(getActivity(), customList.getTitle(), Toast.LENGTH_SHORT).show();
}
This is exactly what you are looking for. Hope that helps.