6. Inventory

Our inventory balance consists of the following:


	September 30,		December 31,
	2018		2017
	(in thousands)
Raw materials	$	481	$	1,062
Work-in-process		4,944		8,615
Finished goods		5,993		4,771
		11,418		14,448
Inventories-current		5,993		6,482
Inventories-non-current	$	5,425	$	7,966

Inventories, stated at the lower of cost and net realizable value, consist of raw materials, work in process and finished goods. At September 30, 2018, $6.0 million of inventory was classified as current on the condensed consolidated balance sheet as we expect this inventory to be consumed for commercial use within the next twelve months. At September 30, 2018, $5.4 million of inventory was classified as non-current on the condensed consolidated balance sheets as we did not expect this inventory to be consumed for commercial use within the next twelve months. We obtain some inventory components from a limited number of suppliers due to technology, availability, price, quality or other considerations. The loss of a supplier, the deterioration of our relationship with a supplier, or any unilateral violation of the contractual terms under which we are supplied components by a supplier could adversely affect our total revenues and gross margins.