Note 5 - Property and Equipment - Property and Equipment (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Buildings	$ 493,000	$ 493,000
Machinery and equipment	13,039,000	12,227,000
Office furniture and equipment	2,076,000	1,390,000
Leasehold improvements	517,000	508,000
Software	3,000	438,000
Property, Plant and Equipment, Gross, Ending Balance	16,128,000	15,056,000
Less accumulated depreciation and amortization	(11,775,000)	(11,113,000)
Total net property and equipment	$ 4,353,000	$ 3,943,000

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation of building structures held for productive use including addition, improvement, or renovation to the structure, including, but not limited to, interior masonry, interior flooring, electrical, and plumbing.

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Amount before accumulated amortization of capitalized costs for computer software, including but not limited to, acquired and internally developed computer software.

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Amount before accumulated depreciation of equipment commonly used in offices and stores that have no permanent connection to the structure of a building or utilities. Examples include, but are not limited to, desks, chairs, tables, and bookcases.

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Amount before accumulated depreciation of additions or improvements to assets held under a lease arrangement.

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