BALANCE SHEET COMPONENTS

6 Months Ended

Jun. 30, 2021

Balance Sheet Related Disclosures [Abstract]

NOTE 3.

BALANCE SHEET COMPONENTS

Property and Equipment, Net

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

	June 30, 2021			December 31, 2020
Prototype	$	17,730		$	17,711
Machinery and equipment		17,822			17,486
Leasehold improvements		14,031			14,196
Furniture and fixtures		1,295			1,295
Software		1,389			1,389
Construction in progress		982			486
Property and equipment, gross		53,249			52,563
Less: accumulated depreciation and amortization		(31,495	)		(28,501	)
Property and equipment, net	$	21,754		$	24,062

Depreciation and amortization expense related to property and equipment was $1.6 million and $1.5 million during the three months ended June 30, 2021 and 2020, and $3.2 million and $3.0 million during the six months ended June 30, 2021 and 2020, respectively.

Accrued Liabilities

Accrued liabilities consisted of the following (in thousands):

	June 30, 2021		December 31, 2020
Accrued payroll and related benefits	$	8,963	$	12,810
Accrued accounts payable		3,964		2,810
Payroll withholding tax, sales and other tax payable		1,332		1,398
Accrued legal, accounting and professional fees		212		305
Product upgrade reserve		2,500		1,500
Other		1,333		458
Total accrued liabilities	$	18,304	$	19,281

Deferred Revenue

Deferred revenue consisted of the following (in thousands):

	June 30, 2021			December 31, 2020
Deferred revenue:
Product	$	343		$	1,888
Service		13,977			8,857
Distribution rights		1,683			1,921
Total deferred revenue		16,003			12,666
Less: current portion of deferred revenue		(11,041	)		(10,094	)
Noncurrent portion of deferred revenue	$	4,962		$	2,572

Other Long-Term Liabilities

Other long-term liabilities consisted of the following (in thousands):

	June 30, 2021		December 31, 2020
Accrued interest, noncurrent portion	$	408	$	99
Asset retirement obligation		918		857
Other accrued costs		1,187		—
Total other-long term liabilities	$	2,513	$	956