Balance Sheet Components

6 Months Ended

12 Months Ended

Jun. 30, 2021

Dec. 31, 2020

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Balance Sheet Components

Note 4. Balance Sheet Components

Cash and Cash Equivalents

The Company’s cash and cash equivalents consist of the following (in thousands):

	June 30, 2021		December 31, 2020
Cash	$	1,293	$	869
Cash equivalents:
Money market funds (1)		238,855		10,493
Total cash and cash equivalents	$	240,148	$	11,362

(1) The Company maintains a cash sweep account which is included in money market funds as of June 30, 2021. Cash is invested in the short-term money market funds, which is a cash sweep for uninvited cash that earns interest.

Restricted Cash

Restricted cash consists of certificates of deposit held by a bank as security for outstanding letters of credit. The Company had a restricted cash balance of $1.3 million and $1.3 million as of June 30, 2021 and December 31, 2020, respectively, which has been excluded from the Company’s cash and cash equivalents balances. The 

Company presented $0.3 million of the total amount of restricted cash within current assets on the condensed consolidated balance sheets as of June 30, 2021 and December 31, 2020. The remaining restricted cash balance of $1.0 million and $1.0 million is included in non-current assets on the condensed consolidated balance sheets as of June 30, 2021 and December 31, 2020, respectively.

Reconciliation of cash, cash equivalents and restricted cash as shown in the condensed consolidated statement of cash flows to the respective accounts within the condensed consolidated balance sheet is as follows (in thousands):

	June 30, 2021		June 30, 2020
Cash and cash equivalents	$	240,148	$	11,438
Restricted cash, current		276		276
Restricted cash, non-current		1,004		1,280
Total cash, cash equivalents and restricted cash	$	241,428	$	12,994

Inventory

Inventory, consisting of material, direct and indirect labor, and manufacturing overhead, consists of the following (in thousands):

	June 30, 2021		December 31, 2020
Raw materials	$	1,887	$	1,376
Work in process		1,360		1,249
Finished goods		1,474		2,192
Total inventory	$	4,721	$	4,817

Total inventory balance as of June 30, 2021 and December 31, 2020 includes a write down of $2.1 million and $2.7 million, respectively, for obsolete, scrap, or returned inventory. During the three months ended June 30, 2021 and 2020, $0.1 million and $0.1 million of inventory write offs were charged to cost of revenue. During the six months ended June 30, 2021 and 2020, respectively, $0.1 million and $1.8 million of inventory write offs were charged to cost of revenue.Prepaid expenses and other current assetsPrepaid expenses and other current assets consist of the following (in thousands):

	June 30, 2021		December 31, 2020
Prepaid insurance	$	3,281	$	206
Prepaid expenses		1,832		694
Receivable from contract manufacturer		43		1,521
Security deposit		1,211		20
Total prepaid and other current assets	$	6,367	$	2,441

Accrued and Other Current Liabilities

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

	June 30, 2021		December 31, 2020
Customer deposits		48		71
Accrued compensation		2,478		1,618
Uninvoiced receipts		2,777		1,947
Other		956		485
Total accrued and other current liabilities	$	6,259	$	4,121

Note 4. Balance Sheet Components

Cash and Cash Equivalents

The Company’s cash and cash equivalents consist of the following (in thousands):

	December 31,
	2019		2020
Cash	$	1,361	$	869
Cash equivalents:
Money market funds		15,411		10,493
Deposits		76		—
Total cash and cash equivalents	$	16,848	$	11,362

Inventory

Inventory, consisting of material, direct and indirect labor, and manufacturing overhead, consists of the following (in thousands):

	December 31,
	2019		2020
Raw materials	$	637	$	1,376
Work in process		1,372		1,249
Finished goods		459		2,192
Total inventory	$	2,468	$	4,817

Total inventory balance as of December 31, 2019 and 2020 includes a write down of $6.4 million and $2.7 million, respectively, for obsolete, scrap, or returned inventory. During the years ended December 31, 2019 and 2020, $4.8 million and $0.8 million of inventory write offs were charged to cost of revenue and included in the write down balance as of December 31, 2019 and 2020.

Prepaid expenses and other current assets

Prepaid expenses and other current assets consist of the following (in thousands):

	December 31,
	2019		2020
Prepaid expenses	$	967	$	900
Security deposit		—		20
Receivable from contract manufacturer		—		1,521
Total prepaid and other current assets	$	967	$	2,441

Property and Equipment, net

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

			December 31,
	Estimated Useful Life (in years)		2019			2020
Machinery and equipment		3	$	2,683		$	5,084
Computer equipment		3		410			456
Automotive and vehicle hardware		5		93			93
Software		3		104			104
Furniture and fixtures		7		721			721
Leasehold improvements		Shorter of useful life or lease term		8,863			9,265
				12,874			15,723
Less: Accumulated depreciation				(2,341	)		(5,992	)
Property and equipment, net			$	10,533		$	9,731

Depreciation expense associated with property and equipment was $2.0 million and $3.7 million in the years ended December 31, 2019 and 2020, respectively. As of December 31, 2020 the Company had tangible assets of $1.3 million held in Thailand and the remainder were in the U.S. Tangible assets outside the U.S. as of December 31, 2019 were not material.

Accrued and Other Current Liabilities

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

	December 31,
	2019		2020
Customer deposits		1,555		71
Accrued compensation		1,152		1,618
Uninvoiced receipts		2,254		1,947
Other		762		485
Total accrued and other current liabilities	$	5,723	$	4,121