CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 2,477,000	$ 959,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	1,304,000	1,358,000
Non-cash operating lease expense	272,000	0
Recovery for doubtful accounts	(9,000)	(14,000)
Deferred taxes	(48,000)	201,000
Foreign currency transaction losses (gains)	(305,000)	29,000
Share-based compensation	558,000	493,000
Unrealized loss on available-for-sale equity security	18,000	5,000
Changes in operating assets and liabilities:
Accounts receivable	1,357,000	320,000
Inventories	(5,006,000)	(1,881,000)
Prepaid expenses and other assets	(782,000)	648,000
Accounts payable	2,666,000	(865,000)
Advance customer payments and other	319,000	186,000
Accrued expenses	780,000	(561,000)
Operating lease liabilities	(395,000)	397,000
Net cash provided by operating activities	3,206,000	1,275,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities of available-for-sale marketable securities	6,216,000	2,860,000
Purchases of available-for-sale marketable securities	(7,980,000)	(2,758,000)
Additions to equipment and leasehold improvements	(477,000)	(957,000)
Additions to patents	(41,000)	(61,000)
Net cash used in investing activities	(2,282,000)	(916,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from exercise of stock options	256,000	59,000
Tax payments for shares withheld related to stock option exercises	(420,000)	0
Net cash (used in) provided by financing activities	(164,000)	59,000
Effects of exchange rate changes on cash and cash equivalents	13,000	(2,000)
Net increase in cash and cash equivalents	773,000	416,000
Cash and cash equivalents – beginning of period	5,836,000	9,248,000
Cash and cash equivalents – end of period	$ 6,609,000	$ 9,664,000