Feed mapping problem

I want to create the following mapping for a product node: This is extracted and amended from an existing feed.

'mappings' => array(    0 => array('source' => 'SKU','target' => 'guid','unique' => 1,'language' => 'und',    ),    1 => array('source' => 'SKU','target' => 'field_product:sku','unique' => FALSE,'language' => 'und',    ),    2 => array('source' => 'title','target' => 'title','unique' => FALSE,'language' => 'und',    ),    3 => array('source' => 'body','target' => 'body','unique' => FALSE,'language' => 'und',    ),    4 => array('source' => 'Group','target' => 'field_product_category','unique' => FALSE,'language' => 'und',    ),    5 => array('source' => 'length','target' => 'field_dimensions_length','unique' => FALSE,'language' => 'und',    ),    6 => array('source' => 'width','target' => 'field_dimensions_width','unique' => FALSE,'language' => 'und',    ),    7 => array('source' => 'height','target' => 'field_dimensions_height','unique' => FALSE,'language' => 'und',    ),    8 => array('source' => 'unit1','target' => 'field_dimensions_unit','unique' => FALSE,'language' => 'und',    ),    9 => array('source' => 'weight','target' => 'field_weight_weight','unique' => FALSE,'language' => 'und',    ),    10 => array('source' => 'unit2','target' => 'field_weight_unit','unique' => FALSE,'language' => 'und',    ),

The first five items are OK and will map via nodes, the others, from 5 to 10 will not.When I go to /Admin/Content/Settings/Content types/Product display/Manage Fields The field_weight element and field_dimensions elements are clearly shown.How can I amend the node mapping to take these fields into consideration.?