Balance Sheet Components

Inventory

Inventory consists of the following (in thousands):



	As of January 31, 2018		As of July 31, 2018
Raw materials	$	1,181	$	2,828
Finished goods	33,316		38,845
Inventory	$	34,497	$	41,673

Property and Equipment, Net

Property and equipment, net, consists of the following (in thousands):



	As of January 31, 2018			As of July 31, 2018
Test equipment	$	142,311		$	156,040
Computer equipment and software	72,329			92,863
Furniture and fixtures	5,363			5,482
Leasehold improvements	15,032			23,763
Total property and equipment	235,035			278,148
Less: accumulated depreciation and amortization	(145,893		)	(176,430		)
Property and equipment, net	$	89,142		$	101,718

Depreciation and amortization expense was $14.8 million and $16.8 million for the three months ended July 31, 2017 and 2018, and $29.2 million and $32.8 million for the six months ended July 31, 2017 and 2018.

Intangible Assets, Net

Intangible assets, net, consist of the following (in thousands):



	As of January 31, 2018			As of July 31, 2018
Technology patents	$	10,125		$	10,125
Accumulated amortization	(5,068		)	(5,820		)
Intangible assets, net	$	5,057		$	4,305

Intangible assets amortization expense was $0.4 million for the three months ended July 31, 2017 and 2018, and $0.8 million for the six months ended July 31, 2017 and 2018. The weighted-average remaining useful life of technology patents is 2.9 years. Due to the defensive nature of these patents, the amortization expense is included in general and administrative expenses in the condensed consolidated statements of operations.

As of July 31, 2018, future expected amortization expense for intangible assets is as follows (in thousands):



Fiscal Years Ending January 31,	Estimated Future Amortization Expense
Remainder of 2019	$	752
2020	1,504
2021	1,504
2022	545
Total	$	4,305

Accrued Expenses and Other Liabilities

Accrued expenses and other liabilities consist of the following (in thousands):



	As of January 31, 2018		As of July 31, 2018
Taxes payable	$	4,052	$	3,801
Accrued marketing	5,928		5,017
Accrued travel and entertainment expenses	4,386		2,556
Other accrued liabilities	12,463		15,675
Total accrued expenses and other liabilities	$	26,829	$	27,049