Condensed Consolidated Statements of Cash Flows - Unaudited - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
OPERATING ACTIVITIES
Net income	$ 1,521	$ 665
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	202	211
Amortization of finite-lived intangible assets	38	38
Recovery of note receivable		(4)
Stock-based compensation	12	13
Unrealized gain on marketable securities	(145)	(86)
Deferred income tax expense	24	18
Changes in operating assets and liabilities:
Increase in accounts receivable, net	(1,647)	(487)
Increase in inventories, net	(1,295)	(427)
(Increase) decrease in prepaid expenses and other assets	(29)	137
Increase in accounts payable, accrued compensation and commissions and other accrued liabilities	1,055	192
Net cash (used in) provided by operating activities	(264)	270
INVESTING ACTIVITIES
Purchase of marketable securities, net	(5,000)
Capital expenditures	(692)	(202)
Net cash used in investing activities	(5,692)	(202)
FINANCING ACTIVITIES
Proceeds from stock option exercise	268	22
Net cash provided by financing activities	268	22
(Decrease) increase in cash and cash equivalents	(5,688)	90
Cash and cash equivalents at beginning of period	15,508	13,250
Cash and cash equivalents at end of period	9,820	13,340
Supplemental Disclosure:
Cash paid for interest	6	17
Cash paid for income taxes	58	$ 34
Non-Cash Disclosure:
Right-of-use assets offset by operating lease liabilities	$ 408