BALANCE SHEETS (Parenthetical) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable, current	$ 22,000	$ 34,000
Inventory valuation reserves	$ 279,000	$ 291,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	37,703,476	32,680,984
Common stock, shares outstanding	37,703,476	32,680,984