Condensed Consolidated Balance Sheets (Parentheticals) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Accounts receivable, allowances (in Dollars)	$ 40,000	$ 38,000
Inventories, reserves for obsolescence (in Dollars)	$ 7,319,000	$ 7,189,000
Preferred stock, par value (in Dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common Class A [Member]
Common stock par value (in Dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares issued	4,990,235	4,867,235
Common stock, shares outstanding	4,990,235	4,867,235
Common Class B [Member]
Common stock par value (in Dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	762,612	762,612
Common stock, shares issued	762,612	762,612
Common stock, shares outstanding	762,612	762,612