CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue
Product sales	$ 7,243	$ 6,699	$ 14,662	$ 13,550
Barrier rentals	1,182	907	6,958	1,650
Royalty income	692	413	1,112	681
Shipping and installation revenue	3,190	2,431	4,791	4,394
Total revenue	12,307	10,450	27,523	20,275
Cost of goods sold	8,993	8,073	18,488	16,297
Gross profit	3,314	2,377	9,035	3,978
Operating expenses
General and administrative expenses	1,340	1,230	2,665	2,282
Selling expenses	696	574	1,291	1,164
Total operating expenses	2,036	1,804	3,956	3,446
Operating income (loss)	1,278	573	5,079	532
Other income (expense)
Interest expense	(56)	(57)	(98)	(113)
Interest income	10	9	19	17
Gain on sale of assets	42	30	88	66
Other income	39	16	33	20
Total other income (expense)	35	(2)	42	(10)
Income (loss) before income tax expense (benefit)	1,313	571	5,121	522
Income tax expense (benefit)	328	130	1,269	119
Net income (loss)	$ 985	$ 441	$ 3,852	$ 403
Basic and diluted earnings (loss) per common share	$ 0.19	$ 0.09	$ 0.74	$ 0.08
Weighted average number of common shares outstanding:
Basic	5,202	5,184	5,202	5,184
Diluted	5,218	5,184	5,214	5,184