Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue
Total revenue	$ 13,209	$ 9,544	$ 34,249	$ 28,502
Cost of goods sold	10,616	6,951	27,278	21,508
Gross profit	2,593	2,593	6,971	6,994
General and administrative expenses	1,123	1,305	3,474	4,059
Selling expenses	717	624	1,924	1,913
Total operating expenses	1,840	1,929	5,398	5,972
Operating income	753	664	1,573	1,022
Other income (expense)
Interest expense	(43)	(44)	(127)	(135)
Interest income	9	10	31	29
Gain on sale of assets	19	51	30	106
Other income	15	11	35	30
Total other income (expense)	0	28	(31)	30
Income before income tax expense	753	692	1,542	1,052
Income tax expense	179	172	364	262
Net income	$ 574	$ 520	$ 1,178	$ 790
Basic and diluted earnings per share	$ 0.11	$ 0.10	$ 0.23	$ 0.16
Diluted earnings per share	$ .11	$ .10	$ .23	$ .15
Weighted average number of common shares outstanding:
Basic (in thousands)	5,134	5,080	5,134	5,078
Diluted (in thousands)	5,138	5,099	5,138	5,098
Product sales
Revenue
Total revenue	$ 8,589	$ 6,828	$ 23,420	$ 21,224
Barrier rentals
Revenue
Total revenue	625	540	1,787	1,188
Royalty income
Revenue
Total revenue	427	465	1,162	1,193
Shipping and installation revenue
Revenue
Total revenue	$ 3,568	$ 1,711	$ 7,880	$ 4,897