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Organization And Summary Of Significant Accounting Policies (Schedule Of Product Warranty Liabilities) (Details) - USD ($)
9 Months Ended 12 Months Ended
Sep. 30, 2019
Dec. 31, 2018
Organization And Summary Of Significant Accounting Policies Schedule Of Product Warranty Liabilities    
Balance at the beginning of the period $ 212,495 $ 328,279
Amount accrued 206,633 59,981
Expenditures 235,225 175,765
Balance at period-end $ 183,903 $ 212,495