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 as of December 31, 2017 and March 31, 2017 (in thousands):

 

 

The non-current portion of inventories represents the portion of the 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 weighted average age of the non-current portion of inventories on hand as of December 31, 2017 is 1.3 years. The Company expects to use the non-current portion of the inventories on hand as of December 31, 2017 over the periods presented in the following table (in thousands):