Quarterly report pursuant to Section 13 or 15(d)

F. ACCRUED LIABILITIES AND EXPENSES (Details)

v3.20.1
F. ACCRUED LIABILITIES AND EXPENSES (Details) - USD ($)
Mar. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Accrued liabilities and expenses      
Accrued liabilities and expenses $ 106,915 $ 214,925  
Accrued payroll and payroll taxes 265,309 227,153  
Accrued sales taxes, penalties, and interest 8,890 26,957  
Product warranties 61,742 58,791 $ 46,103
Total accrued liabilities and expenses $ 442,856 $ 527,826