Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue
Total revenue	$ 10,189	$ 9,125
Cost of goods sold	7,967	7,534
Gross profit	2,222	1,591
General and administrative expenses	1,354	1,468
Selling expenses	420	676
Total operating expenses	1,775	2,144
Operating income (loss)	447	(553)
Other income (expense)
Interest expense	(44)	(46)
Interest income	11	10
Gain on sale of assets	2	24
Other income	14	8
Total other income (expense)	(17)	(4)
Income (loss) before income tax expense	430	(557)
Income tax expense (benefit)	99	(135)
Net income (loss)	$ 331	$ (422)
Basic and diluted earnings per share	$ .06	$ (.08)
Weighted average number of common shares outstanding:
Basic (in thousands)	5,134	5,114
Diluted (in thousands)	5,142	5,114
Product sales
Revenue
Total revenue	$ 7,503	$ 7,453
Barrier rentals
Revenue
Total revenue	573	309
Royalty income
Revenue
Total revenue	306	221
Shipping and installation revenue
Revenue
Total revenue	$ 1,807	$ 1,142