Note 4 - Inventories - Inventories (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Raw materials	$ 4,284,000	$ 4,732,000
Work in process	2,559,000	825,000
Finished goods	4,460,000	4,321,000
Total inventory	$ 11,303,000	$ 9,878,000	[1]

[1] The condensed consolidated balance sheet as of December 31, 2018 has been prepared using information from the audited consolidated balance sheet as of that date.