Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 6,363	$ 6,826
Trade accounts receivable, net	4,566	6,466
Inventories, net	10,511	9,441
Prepaid expenses and other current assets	1,821	1,878
Total current assets	23,261	24,611
Property, plant and equipment, net	4,299	3,566
Right-of-use (ROU) asset	2,689	2,887
Investment in securities	2,219	2,014
Deferred tax assets, net	4,300	4,300
Other assets	118	112
Total assets	36,886	37,490
Current liabilities:
Accounts payable	5,418	5,119
Accrued compensation and related taxes	1,320	1,635
Accrued warranty expense	718	791
Accrued other expenses and other current liabilities	162	307
Dividends payable	251	250
Short-term lease liability	418	525
Credit facility	800	0
Note payable-current portion	82	82
Deferred revenue	847	757
Total current liabilities	10,016	9,466
Note payable, net of current portion	226	247
Long-term lease liability	2,607	2,702
Deferred revenue	2,323	2,551
Total liabilities	15,172	14,966
Stockholders' equity:
Preferred stock; $1.00 par value; 1,000,000 authorized shares; none issued or outstanding	0	0
Common stock; $.60 par value; 20,000,000 authorized shares; 13,986,871 and 13,962,366 issued and 12,536,471 and 12,511,966 outstanding shares at March 31, 2021 and December 31, 2020, respectively	8,392	8,377
Additional paid-in capital	26,466	26,346
Accumulated deficit	(7,742)	(6,797)
Treasury stock, at cost, 1,450,400 shares at March 31, 2021, and December 31, 2020, respectively	(5,402)	(5,402)
Total stockholders' equity	21,714	22,524
Total liabilities and stockholders' equity	$ 36,886	$ 37,490