Inventory

The components of inventory consisted of the following:



	As of		As of
(in thousands)	December 31, 2017		September 30, 2017
Raw materials	$	13,663	$	15,826
Work in-process	6,015		6,586
Finished goods	6,233		5,413
Inventory balance at end of period	$	25,911	$	27,825
Current portion	$	23,401	$	25,139
Non-Current portion	$	2,510	$	2,686

The non-current inventory balance of $2.5 million and $2.7 million as of December 31, 2017 and September 30, 2017, respectively, is comprised entirely of raw materials which we acquired as part of a last time purchase as a result of the vendor announcing they would cease manufacturing a part.