CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract]
Net sales	$ 9,702	$ 8,301
Cost of sales	6,708	5,112
Gross profit	2,994	3,189
Operating expenses:
Engineering, design and product development	2,283	1,803
Selling and marketing	2,683	1,443
General and administrative	3,204	2,609
Operating expenses	8,170	5,855
Operating loss	(5,176)	(2,666)
Interest and other (expense) income:
Interest, net	(64)	(13)
Other, net	(35)	(83)
Interest and other income (expense)	(99)	(96)
Loss before income taxes	(5,275)	(2,762)
Income tax benefit	(1,262)	(556)
Net loss	$ (4,013)	$ (2,206)
Net loss per common share:
Basic (in dollars per share)	$ (0.41)	$ (0.25)
Diluted (in dollars per share)	$ (0.41)	$ (0.25)
Shares used in per-share calculation:
Basic (in shares)	9,886	8,948
Diluted (in shares)	9,886	8,948