3. Inventories

Inventories are valued on a FIFO basis and lower of cost or market and consisted of the following as of March 31, 2017 and 2016 (in thousands):

 

The non‑current portion of inventories represents that portion of the inventories in excess of amounts expected to be 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 March 31, 2017 is 1.9 years. The Company expects to use the non‑current portion of the inventories on hand as of March 31, 2017 over the periods presented in the following table (in thousands):