Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 182,019	$ 156,720
Accounts receivable	16,569	11,769
Inventory, net of allowance of $2,334 and $2,286, respectively	43,858	46,641
Deposits on purchased inventory	2,550	2,084
Deferred cost of revenue	2,310	1,954
Prepaid expenses and other current assets	5,273	5,257
Total current assets	252,579	224,425
Property and equipment, net	22,822	24,062
Restricted cash	1,460	1,460
Intangible assets, net	48	50
Right-of-use assets	9,553	10,129
Other assets	1,428	1,426
TOTAL ASSETS	287,890	261,552
Current liabilities:
Accounts payable	7,591	9,984
Accrued liabilities	14,164	19,281
Customer deposits	15,433	15,463
Operating lease liability, current	1,988	2,089
Current portion of long-term debt	0	0
Deferred revenue, current	10,022	10,094
Total current liabilities	49,198	56,911
Deferred revenue, net of current portion	2,089	2,572
Long-term debt	57,022	56,940
Warrant liabilities	5,484	4,864
Operating lease liability, noncurrent	8,546	9,043
Other long-term liabilities	1,146	956
TOTAL LIABILITIES	123,485	131,286
Commitments and contingencies (Note 6)	0	0
Stockholders’ equity:
Preferred stock, par value of $0.01 per share; 10,000,000 shares authorized at March 31, 2021 and December 31, 2020; no shares issued and outstanding at March 31, 2021 and December 31, 2020	0	0
Common stock, par value of $0.01 per share; 300,000,000 shares authorized at March 31, 2021 and December 31, 2020; 161,730,363 and 148,615,351 shares issued and outstanding at March 31, 2021 and December 31, 2020	1,607	1,476
Additional paid-in capital	816,625	755,874
Accumulated deficit	(653,827)	(627,084)
TOTAL STOCKHOLDERS’ EQUITY	164,405	130,266
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 287,890	$ 261,552