Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating Activities:
Net (loss) income	$ (32,954)	$ 1,280
Adjustments to reconcile net (loss) income to net cash used in operating activities:
Depreciation and amortization	2,950	2,866
Amortization of right-of-use lease assets	19	151
Amortization of debt issuance costs and premium	361	0
Change in fair value of warrants	(2,717)	(27,933)
Gain on expiration of warrant	(5,018)	0
Amortization of discount on short-term investments	(19)	(430)
Stock-based compensation	4,658	2,948
Provision for excess and obsolete inventory	2,357	28
Change in operating assets and liabilities:
Accounts receivable	(1,492)	(650)
Inventories	(3,511)	(1,940)
Prepaid and other assets	(3,155)	493
Accounts payable	454	(597)
Accrued expenses and other liabilities	2,081	(3,192)
Net cash used in operating activities	(35,986)	(26,976)
Investing Activities:
Purchases of property and equipment	(1,575)	(2,001)
Proceeds from maturities of short-term investments	55,000	95,000
Purchases of short-term investments	(99,986)	(62,892)
Net cash (used in) provided by investing activities	46,561	30,107
Financing Activities:
Proceeds from term loan	15,000	0
Payments of debt issuance costs	(124)	0
Proceeds from Warrant Exercises	790	0
Proceeds from Issuance Initial Public Offering	119,582	0
Principal payments on finance lease liabilities	(21)	(131)
Payments of deferred offering costs	(242)	0
Change in notes receivables for redeemable common stock issued	575	65
Proceeds from exercise of stock options	1,378	975
Net cash provided by financing activities	136,938	909
Effect of foreign exchange rate on cash, cash equivalents and restricted cash	(7)	(7)
Net increase in cash, cash equivalents and restricted cash	54,384	4,033
Cash, cash equivalents and restricted cash - beginning of period	14,455	8,830
Cash, cash equivalents and restricted cash - end of period	68,839	12,863
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	932	740
Cash paid for income taxes	19	58
Cash paid for interest on financing leases	4	12
Cash paid for interest on term loan	2,237	0
Right-of-use assets obtained in exchange for lease obligations:
Operating lease	103	1,923
Finance Lease	0	48
Lease obligations recorded for right-of-use assets:
Operating lease	103	1,923
Finance Lease	0	(48)
Acquisition of property and equipment included in accounts payable and accrued expenses and other current liabilities	138	212
Accretion to redemption value of redeemable stock and stock options	0	39,181
Payment-in-kind interest income added to principal of notes receivable	28	41
Reclassification from warrant liability to additional paid-in capital for warrants exercised	1,111	24
Reclassification of 4,093,995 shares of redeemable common stock to 4,093,995 shares of common stock	87,702	0
Reclassification of redeemable common stock options to common stock options	47,370	0
Conversion of preferred stock to common stock upon initial public offering	357,202	0
Reclassification of deferred financing costs	$ 3,156	$ 0