Annual report pursuant to Section 13 and 15(d)

A. BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES (Details-Product warranties)

v3.20.1
A. BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES (Details-Product warranties) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Product warranties    
Beginning balance $ 46,103 $ 59,892
Warranty claims incurred (66,803) (28,000)
Provision charged to expense 79,491 14,211
Ending balance $ 58,791 $ 46,103