Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue
Total revenue	$ 10,852	$ 9,833	$ 21,041	$ 18,958
Cost of goods sold	8,696	6,857	16,663	14,391
Gross profit	2,156	2,976	4,378	4,567
General and administrative expenses	1,143	1,452	2,350	2,919
Selling expenses	640	613	1,207	1,290
Total operating expenses	1,783	2,065	3,557	4,209
Operating income	373	911	821	358
Other income (expense)
Interest expense	(40)	(44)	(85)	(90)
Interest income	11	9	21	19
Gain on sale of assets	10	31	12	55
Other income	5	9	20	18
Total other income (expense)	(14)	5	(32)	2
Income before income tax expense	359	916	789	360
Income tax expense	86	225	185	90
Net income	$ 273	$ 691	$ 604	$ 270
Basic and diluted earnings per share	$ 0.05	$ 0.14	$ 0.12	$ 0.05
Weighted average number of common shares outstanding:
Basic (in thousands)	5,134	5,080	5,134	5,076
Diluted (in thousands)	5,143	5,104	5,141	5,101
Product sales
Revenue
Total revenue	$ 7,327	$ 6,943	$ 14,831	$ 14,396
Barrier rentals
Revenue
Total revenue	582	340	1,163	649
Royalty income
Revenue
Total revenue	429	506	735	727
Shipping and installation revenue
Revenue
Total revenue	$ 2,514	$ 2,044	$ 4,312	$ 3,186