Inventories, Net and Significant Suppliers (Tables)

12 Months Ended

Dec. 31, 2019

Inventories, net were as follows:



	December 31,
(In thousands)	2019			2018
Raw materials	$	61,220		$	68,834
Components	25,239			25,071
Work in process	1,526			5,577
Finished goods	68,175			50,006
Reserve for excess and obsolete inventory	(11,025		)	(5,138		)
Inventories, net	$	145,135		$	144,350

Changes in the reserve for excess and obsolete inventory were as follows:



	Year Ended December 31,
(In thousands)	2019			2018			2017
Balance at beginning of period	$	5,138		$	4,288		$	4,205
Additions charged to costs and expenses	12,792			6,702			3,685
Sell through⁽¹⁾	(1,500		)	(1,825		)	(1,242		)
(Write-offs)/Foreign exchange effects	(5,405		)	(4,027		)	(2,360		)
Balance at end of period	$	11,025		$	5,138		$	4,288


⁽¹⁾	These amounts represent the reversal of reserves associated with inventory items that were sold during the period.

Purchases from the following supplier totaled more than 10% of our total inventory purchases:



	Year Ended December 31,
	2019				2018				2017
	$ (thousands)		% of Total Inventory Purchases		$ (thousands)		% of Total Inventory Purchases		$ (thousands)		% of Total Inventory Purchases
Texas Instruments	—	⁽¹⁾	—	⁽¹⁾	—	⁽¹⁾	—	⁽¹⁾	$	42,058	10.0	%

⁽¹⁾ Purchases associated with this supplier did not total more than 10% of our total inventory purchases for the indicated period.