Condensed Balance Sheets - USD ($) $ in Thousands	Mar. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 35,409	$ 54,271
Accounts receivable	16,194	12,626
Inventory	34,281	30,257
Prepaid expenses and other current assets	6,525	5,672
Total current assets	92,409	102,826
Property, plant, and equipment, net	31,861	30,527
Other non-current assets, net	887	396
Total assets	125,157	133,749
Current liabilities:
Accounts payable	11,663	17,247
Wages payable	1,085	1,255
Accrued bonus	3,387	2,312
Accrued expenses and other current liabilities	3,094	2,391
Short-term capital lease liabilities	36	44
Stock warrant liability	2,677	1,918
Total current liabilities	21,942	25,167
Long-term liabilities:
Revolving credit line	6,000	6,000
Long-term portion of bank term loan, net	19,533	19,388
Equipment loan, net	4,914	5,000
Capital lease obligations and other long-term liabilities	406	404
Total long-term liabilities	30,853	30,792
Commitments and Contingencies (Note 9)
Convertible preferred stock:
Convertible preferred stock	199,540	199,540
Stockholders’ deficit:
Common stock, par value $0.0001 per share—60,000,000 shares and 58,669,600 shares authorized at March 30, 2019 and December 31, 2018, respectively; 7,120,933 and 6,951,350 shares issued and outstanding at March 30, 2019 and December 31, 2018, respectively	1	1
Additional paid-in capital	9,142	7,921
Accumulated deficit	(136,321)	(129,672)
Total stockholders’ deficit	(127,178)	(121,750)
Total liabilities, convertible preferred stock and stockholders’ deficit	125,157	133,749
Series A
Convertible preferred stock:
Convertible preferred stock	2,000	2,000
Series B
Convertible preferred stock:
Convertible preferred stock	4,999	4,999
Series C
Convertible preferred stock:
Convertible preferred stock	14,882	14,882
Series D
Convertible preferred stock:
Convertible preferred stock	24,948	24,948
Series E
Convertible preferred stock:
Convertible preferred stock	17,214	17,214
Series F
Convertible preferred stock:
Convertible preferred stock	29,840	29,840
Series G
Convertible preferred stock:
Convertible preferred stock	55,658	55,658
Series H
Convertible preferred stock:
Convertible preferred stock	$ 49,999	$ 49,999