Note 4 - Inventories - Components of Inventories (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Raw materials	$ 2,016,488	$ 3,156,016
Work-in-process	205,385	389,630
Finished goods		26,977
Gross inventories	2,221,873	3,572,623
Less reserve for obsolescence	(360,000)	(607,000)
Inventories, net	$ 1,861,873	$ 2,965,623

Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer.

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Gross amount, as of the balance sheet date, of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.

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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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Amount before valuation and LIFO reserves of raw materials expected to be sold, or consumed within one year or operating cycle, if longer.

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Amount before valuation and LIFO reserves of merchandise or goods in the production process expected to be completed within one year or operating cycle, if longer.

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