	As of
	September 27, 2020		December 31, 2019
	(In thousands)
Raw materials	$	11,149	$	28,871
Finished goods		133,153		206,618
Total	$	144,302	$	235,489

The Company records provisions for excess and obsolete inventory based on assumptions about future demand and market conditions and the amounts incurred were $1.8 million and $6.4 million for the three and nine months ended September 27, 2020, respectively, and $0.9 million and $2.9 million for the three and nine months ended September 29, 2019, respectively. While management believes the estimates and assumptions underlying its current forecasts are reasonable, there is risk that additional charges may be necessary if current forecasts are greater than actual demand.

	As of
	September 27, 2020			December 31, 2019
	(In thousands)
Computer equipment	$	10,433		$	9,883
Furniture, fixtures and leasehold improvements		18,266			18,623
Software		29,227			27,865
Machinery and equipment		69,213			59,637
Total property and equipment, gross		127,139			116,008
Accumulated depreciation and amortization		(111,826	)		(98,325	)
Total	$	15,313		$	17,683

Depreciation and amortization expense pertaining to property and equipment was $3.3 million and $9.5 million for the three and nine months ended September 27, 2020, respectively, and $3.0 million and $9.1 million for the three and nine months ended September 29, 2019, respectively.

	As of September 27, 2020							As of December 31, 2019
	Gross		Accumulated Amortization			Net		Gross		Accumulated Amortization			Net
	(In thousands)
Technology	$	59,799	$	(57,728	)	$	2,071	$	59,799	$	(57,406	)	$	2,393
Customer contracts and relationships		56,800		(54,269	)		2,531		56,800		(50,297	)		6,503
Other		10,345		(9,557	)		788		10,345		(9,137	)		1,208
Total	$	126,944	$	(121,554	)	$	5,390	$	126,944	$	(116,840	)	$	10,104

Amortization of intangibles was $1.5 million and $4.7 million for the three and nine months ended September 27, 2020, respectively, and $1.6 million and $5.4 million for the three and nine months ended September 29, 2019, respectively.

As of September 27, 2020, estimated amortization expense related to finite-lived intangibles for the remaining years is as follows (in thousands):

2020 (remaining three months)	$	1,491
2021		2,044
2022		527
2023		514
2024		514
Thereafter		300
Total estimated amortization expense	$	5,390

	As of
	September 27, 2020		December 31, 2019
	(In thousands)
Non-current deferred income taxes	$	57,375	$	58,930
Long-term investments		9,060		8,147
Other		6,519		7,202
Total	$	72,954	$	74,279

The Company’s long-term investments are primarily comprised of equity investments without readily determinable fair values. The changes in the carrying value of these investments during the periods represented are as follows:

	Nine Months Ended
	September 27, 2020			September 29, 2019
	(In thousands)
Carrying value as of the beginning of the period	$	8,147		$	2,886
Additions from purchase of investments		5,850			5,484
Impairment and downward adjustments for price changes		(5,372	)		(223	)
Carrying value as of the end of the period ⁽¹⁾	$	8,625		$	8,147

⁽¹⁾The balance as of September 27, 2020 did not include the investment in limited partnership fund of $0.4 million.

The impairment recognized during the nine months ended September 27, 2020 was brought about by triggering events impacting the valuation of a number of our privately held long-term investments, partially impacted by the COVID-19 pandemic. For the equity investments without readily determinable fair values as of September 27, 2020, cumulative downward adjustments for price changes and impairment was $7.0 million and cumulative upward adjustments for price changes was $0.2 million.

	As of
	September 27, 2020		December 31, 2019
	(In thousands)
Current operating lease liabilities	$	8,849	$	9,357
Sales and marketing		68,787		85,605
Warranty obligations		9,658		10,556
Sales returns⁽¹⁾		61,646		52,612
Freight and duty		17,293		5,633
Other		30,064		25,784
Total	$	196,297	$	189,547

⁽¹⁾Inventory expected to be received from future sales returns amounted to $30.7 million and $26.8 million as of September 27, 2020 and December 31, 2019, respectively. Provisions to write down expected returned inventory to net realizable value amounted to $16.6 million and $14.9 million as of September 27, 2020 and December 31, 2019, respectively.