5.  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 represent the portion of inventories in excess of amounts expected to be sold or used in the next twelve months and is primarily comprised of repair parts for older generation products still in operation but not technologically compatible with current configurations. The non-current portion also includes inventory that has long lead times. The weighted average age of the non-current portion of inventories on hand as of December 31, 2022 is 0.8 years. The Company expects to use the non-current portion of the inventories on hand as of December 31, 2022 over the periods presented in the following table (in thousands):

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