Note 6. Inventories

Inventories, net of inventory writedowns, consist of the following for the periods indicated (in thousands):



	June 30, 2018		December 31, 2017
Raw materials	$	27,078	$	26,648
Work in process and sub-assemblies		48,068		31,060
Finished goods		18,123		18,060
	$	93,269	$	75,768

The lower of cost or market adjustment expensed for inventory for the three months ended June 30, 2018 and 2017 was $1.5 million and $0.2 million, respectively. The lower of cost or market adjustment expensed for inventory for the six months ended June 30, 2018 and 2017 was $2.4 million and $0.7 million, respectively.