Inventories, Net and Significant Suppliers

Inventories, net were as follows:



(In thousands)	September 30, 2019			December 31, 2018
Raw materials	$	59,412		$	68,834
Components	21,557			25,071
Work in process	5,757			5,577
Finished goods	60,306			50,006
Reserve for excess and obsolete inventory	(9,510		)	(5,138		)
Inventories, net	$	137,522		$	144,350

Reserve for Excess and Obsolete Inventory

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



(In thousands)	Nine Months Ended September 30,
(In thousands)	2019			2018
Balance at beginning of period	$	5,138		$	4,288
Additions charged to costs and expenses ⁽¹⁾	7,430			5,353
Sell through ⁽²⁾	(1,220		)	(1,240		)
(Write-offs)/Foreign exchange effects	(1,838		)	(1,118		)
Balance at end of period	$	9,510		$	7,283


⁽¹⁾	The additions charged to costs and expenses do not include inventory directly written-off that was scrapped during production totaling $3.8 million and $1.1 million for the nine months ended September 30, 2019 and 2018, respectively. These amounts are production waste and manufacturing inefficiencies and are not included in management's reserve for excess and obsolete inventory.


⁽²⁾	These amounts represent the reduction in reserves associated with inventory items that were sold during the period.

Significant Suppliers

We purchase integrated circuits, components and finished goods from multiple sources. No suppliers totaled more than 10% of our total inventory purchases for the three and nine months ended September 30, 2019 and 2018.

Related Party Supplier

During the nine months ended September 30, 2018, we purchased certain printed circuit board assemblies from a related party supplier. The supplier was considered a related party for financial reporting purposes because our Senior Vice President of Strategic Operations owned 40% of this supplier. In the second quarter of 2018, our Senior Vice President sold his interest in this supplier, and thus this supplier is no longer considered a related party.

Total inventory purchases made from this supplier while it was a related party were $1.1 million during the nine months ended September 30, 2018.