CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - UNAUDITED - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
OPERATING ACTIVITIES
Net income	$ 665	$ 131
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	211	325
Amortization of finite-lived intangible assets	38	38
Recovery of other assets	(4)
Stock-based compensation	13	15
Gain on marketable securities	(86)
Deferred income tax provision	18	18
Changes in operating assets and liabilities:
(Increase) decrease in accounts receivable, net	(487)	439
Increase in inventories, net	(427)	(444)
Decrease (increase) in prepaid expenses and other assets	137	(23)
Increase (decrease) in accounts payable, accrued compensation and commissions and other accrued liabilities	192	(89)
Net cash provided by operating activities	270	410
INVESTING ACTIVITIES
Purchase of marketable securities	(11,775)	(1,002)
Capital expenditures	(202)	(28)
Net cash used in investing activities	(11,977)	(1,030)
FINANCING ACTIVITIES
Proceeds from stock option exercise	22
Net cash provided by financing activities	22
Decrease in cash and cash equivalents	(11,685)	(620)
Cash and cash equivalents at beginning of period	13,250	2,778
Cash and cash equivalents at end of period	1,565	2,158
Supplemental Disclosure:
Cash paid for interest	17	17
Cash paid for income taxes	$ 34	$ 20