Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 31,967	$ 12,084
Short-term investments	8,256	17,567
Accounts receivable	107	118
Inventory	12,095	8,901
Prepaid expenses and other current assets	411	614
Total current assets	52,836	39,284
Property and equipment - net	625	647
Deferred tax assets	618	588
Right-of-use assets	645	959
Other assets	213	1,741
Total assets	54,937	43,219
Current liabilities:
Accounts payable	2,233	1,457
Accrued liabilities	2,080	2,523
Liability related to early exercised stock options	6	19
Customer deposits	3,206	735
Lease liabilities	604	720
Total current liabilities	8,129	5,454
Other liabilities	171	392
Total liabilities	8,300	5,846
Commitments and contingencies (Note 5)
Stockholders’ equity
Preferred stock, par value $0.0001 per share - 5,000,000 shares authorized as of June 30, 2021 and December 31, 2020; nil shares issued and outstanding as of June 30, 2021 and December 31, 2020
Common stock, par value $0.0001 per share - 75,000,000 shares authorized as of June 30, 2021 and December 31, 2020; 17,820,485 and 17,690,062 shares issued and outstanding as of June 30, 2021 and December 31, 2020, respectively	2	2
Additional paid-in capital	23,341	22,523
Accumulated other comprehensive income	8	41
Retained earnings	23,286	14,807
Total stockholders’ equity	46,637	37,373
Total liabilities and stockholders’ equity	$ 54,937	$ 43,219