Balance Sheet Components

6 Months Ended

Jun. 30, 2019

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Inventory

As of June 30, 2019 and December 31, 2018, inventory consisted entirely of finished goods.

Property and Equipment, net (in thousands):



	June 30,			December 31,
	2019			2018
Machinery and equipment	$	4,097		$	3,785
Construction in progress	854			730
Computer and office equipment	440			407
Leasehold improvements	497			448
Furniture and fixtures	151			148
	6,039			5,518
Less: Accumulated depreciation and amortization	(3,507		)	(3,364		)
	$	2,532		$	2,154

Depreciation expense was $0.2 million and $0.2 million for the three months ended June 30, 2019 and 2018, respectively and $0.4 million and $0.4 million for the six months ended June 30, 2019 and 2018, respectively.

Accrued Liabilities and Other (in thousands):



	June 30,		December 31,
	2019		2018
Accrued compensation and related expenses	$	4,987	$	5,425
Accrued interest	1,163		—
Accrued professional services	421		583
Sales tax payable	349		388
Liability for early exercise of unvested stock options	210		331
Others	339		133
	$	7,469	$	6,860