How to import Product Kit via CSV file?
Ubercart Feeds Mapper module:

Refer to the answer to the question about "How to import products to UberCart 3 using CSV data?". It contains a link to Drupal 7 Port of uc_feeds, which seems to include everything that's needed to make this to work by using the Ubercart Feeds Mapper module.

Note: from your recent question "Ubercart Product import containing HTML formatting in product description", I'm assuming that you are referring to the Ubercart Feeds Mapper module (instead of "Ubercart 'product' mapper" ...

From Ubercart.org:

Importing from CSV files also details the steps required for such import. The process consists of 3 steps. Here is a summary of these steps:


Prepare product data.
Activate the Node Import module.
Import process.


Attention, the 'Node Import' module does not have a D7 version, only a D6 version.