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Balance Sheet Components - Components of Accrued Liabilities (Details) - USD ($)
$ in Thousands
Sep. 30, 2019
Dec. 31, 2018
Balance Sheet Related Disclosures [Abstract]    
Payroll-related expenses $ 485 $ 398
Accrued warranty 206 73
Engineering services 197 134
Taxes payable 56 28
Professional fees 51 48
Other 53 37
Total accrued liabilities $ 1,048 $ 718