CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
CONSOLIDATED STATEMENTS OF INCOME [Abstract]
Net sales	$ 10,637	$ 7,300	$ 28,263	$ 22,832
Cost of sales	6,320	3,951	17,432	12,275
Gross profit	4,317	3,349	10,831	10,557
Operating expenses:
Engineering, design and product development	1,876	1,445	5,483	4,197
Selling and marketing	1,899	1,258	5,109	4,885
General and administrative	2,146	2,125	7,264	6,987
Operating expenses	5,921	4,828	17,856	16,069
Operating loss	(1,604)	(1,479)	(7,025)	(5,512)
Interest and other expense:
Interest, net	(29)	(19)	(71)	(41)
Gain (Loss) on Non-Recourse Debt	2,173	0	2,173	0
Other, net	(69)	116	(169)	(60)
Interest and other expense	2,075	97	1,933	(101)
Loss before income taxes	471	(1,382)	(5,092)	(5,613)
Income tax benefit	(439)	(515)	(1,682)	(1,901)
Net loss	$ 910	$ (867)	$ (3,410)	$ (3,712)
Net loss per common share:
Basic (in dollars per share)	$ 0.10	$ (0.11)	$ (0.37)	$ (0.49)
Diluted (in dollars per share)	$ 0.09	$ (0.11)	$ (0.37)	$ (0.49)
Shares used in per-share calculation:
Basic (in shares)	9,408	7,548	9,112	7,533
Diluted (in shares)	9,846	7,548	9,112	7,533