Note 5 - Property and Equipment - Property and Equipment (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Buildings	$ 493,000	$ 493,000
Machinery and equipment	11,231,000	11,036,000
Office furniture and equipment	1,260,000	1,151,000
Leasehold improvements	508,000	507,000
Software	373,000	177,000
	13,865,000	13,364,000
Less accumulated depreciation and amortization	(10,621,000)	(10,206,000)
	$ 3,244,000	$ 3,158,000

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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