SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity method investment, ownership percentage			25.00%
Accounts receivable, net	$ 38,218	$ 22,724
Cash and cash equivalents deposited with financial institutions	7,818	4,942	$ 16,156
Allowance for Doubtful Accounts Receivable, Current	377	140
Right-of-use assets	5,743
Lease liabilities	5,898
Restricted Cash
Restricted cash	$ 468	467
Minimum
Vesting period	1 year
Maximum
Product warranty term	2 years
Vesting period	4 years
Collateral for Letter of Credit and Credit Card Obligations
Restricted Cash
Restricted cash	$ 500	$ 500
United States
Percentage of revenue	93.10%	100.00%
Cash and cash equivalents deposited with financial institutions	$ 4,400
Canada
Percentage of revenue	7.90%
Cash and cash equivalents deposited with financial institutions	$ 2,900
Other Noncurrent Assets
Equity method investment	2,300	$ 800
Equity Method Investee
Accounts receivable, net	2,700	2,100
Net income	1,500	$ 1,000
Dividends received	$ 500

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

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