6.  Inventories

Inventories are valued at the lower of cost (determined on a first-in, first-out (“FIFO”) basis) or net realizable value and consisted of the following (in thousands):

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The non-current portion of inventories represents that portion of inventories in excess of amounts expected to be sold or used in the next twelve months. The non-current inventories are primarily comprised of repair parts for older generation products that are still in operation but are not technologically compatible with current configurations. The Company expects to use the non-current portion of the inventories on hand as of December 31, 2023 over the periods presented in the following table (in thousands):

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