Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 25,256	$ 12,084
Short-term investments	15,402	17,567
Accounts receivable	245	118
Inventory	12,226	8,901
Prepaid expenses and other current assets	490	614
Total current assets	53,619	39,284
Property and equipment - net	579	647
Deferred tax assets	830	588
Right-of-use assets	1,186	959
Other assets	2,569	1,741
Total assets	58,783	43,219
Current liabilities:
Accounts payable	2,007	1,457
Accrued liabilities	2,964	2,523
Liability related to early exercised stock options	2	19
Customer deposits	1,113	735
Lease liabilities	628	720
Total current liabilities	6,714	5,454
Other liabilities	687	392
Total liabilities	7,401	5,846
Commitments and contingencies (Note 5)
Stockholders’ equity
Preferred stock, par value $0.0001 per share - 5,000,000 shares authorized as of September 30, 2021 and December 31, 2020; nil shares issued and outstanding as of September 30, 2021 and December 31, 2020
Common stock, par value $0.0001 per share - 75,000,000 shares authorized as of September 30, 2021 and December 31, 2020; 17,891,216 and 17,690,062 shares issued and outstanding as of September 30, 2021 and December 31, 2020, respectively	2	2
Additional paid-in capital	23,842	22,523
Accumulated other comprehensive income (loss)	(4)	41
Retained earnings	27,542	14,807
Total stockholders’ equity	51,382	37,373
Total liabilities and stockholders’ equity	$ 58,783	$ 43,219