Inventories, Net and Significant Suppliers

Inventories, net were as follows:



(In thousands)	March 31, 2018			December 31, 2017
Raw materials	$	46,886		$	43,638
Components	11,972			16,214
Work in process	252			1,847
Finished goods	84,526			105,178
Reserve for excess and obsolete inventory	(4,228		)	(4,288		)
Inventories, net	$	139,408		$	162,589

Reserve for Excess and Obsolete Inventory

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



(In thousands)	Three Months Ended March 31,
(In thousands)	2018			2017
Balance at beginning of period	$	4,288		$	4,205
Additions charged to costs and expenses ⁽¹⁾	643			632
Sell through ⁽²⁾	(315		)	(354		)
(Write-offs)/Foreign exchange effects	(388		)	(274		)
Balance at end of period	$	4,228		$	4,209


⁽¹⁾	The additions charged to costs and expenses do not include inventory directly written-off that was scrapped during production totaling $113 thousand and $27 thousand for the three months ended March 31, 2018 and 2017, respectively. These amounts are production waste 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. Purchases from the following supplier totaled more than 10% of our total inventory purchases:



	Three Months Ended March 31,
	2018				2017
	$ (thousands)		% of Total Inventory Purchases		$ (thousands)		% of Total Inventory Purchases
Texas Instruments ⁽¹⁾	$	—	—	%	$	9,128	10.4	%


⁽¹⁾	Purchases associated with this supplier did not total more than 10% of our total inventory purchases for the three months ended March 31, 2018.

Related Party Supplier

We purchase certain printed circuit board assemblies from a related party supplier. The supplier is considered a related party for financial reporting purposes because our Senior Vice President of Strategic Operations owns 40% of this vendor. Inventory purchases from this supplier were as follows:



	Three Months Ended March 31,
	2018				2017
	$ (thousands)		% of Total Inventory Purchases		$ (thousands)		% of Total Inventory Purchases
Related party supplier	$	1,117	1.2	%	$	946	1.1	%

Total accounts payable to this supplier were as follows:



	March 31, 2018				December 31, 2017
	$ (thousands)		% of Accounts Payable		$ (thousands)		% of Accounts Payable
Related party supplier	$	1,781	1.7	%	$	1,500	1.3	%

Our payable terms and pricing with this supplier are consistent with the terms offered by other suppliers in the ordinary course of business. The accounting policies that we apply to our transactions with our related party supplier are consistent with those applied in transactions with independent third parties. Corporate management routinely monitors purchases from our related party supplier to ensure these purchases remain consistent with our business objectives.