2. Inventories, net

12 Months Ended

Dec. 31, 2020

Inventory Disclosure [Abstract]

2. Inventories, net

Inventories, which are presented net of allowance for obsolete and slow-moving inventory, consisted of the following:

	December 31,
	2020		2019
Finished goods	$	1,975	$	3,864
Work in process		3,288		6,122
Raw materials		4,178		3,527
	$	9,441	$	13,513

Changes in the allowance for obsolete and slow-moving inventory are as follows:

	Years Ended December 31,
	2020			2019
Balance, beginning of year	$	823		$	629
Charged to cost of sales		126			194
Disposal of inventory		(429	)		—
Balance, end of year	$	520		$	823

For the year ended December 31, 2020, the Company wrote off obsolete inventory that had been fully allowed for previously, which had no material impact to the Company’s consolidated balance sheets or consolidated statements of operations.