Annual report pursuant to Section 13 and 15(d)

Product warranty (Tables)

v3.22.0.1
Product warranty (Tables)
12 Months Ended
Dec. 31, 2021
Guarantees [Abstract]  
Schedule of Product Warranty Reserve
Changes in our warranty reserve were as follows:
Warranty reserve, December 31, 2019 $ 205,300 
Warranty provision for units sold 185,696 
Costs of warranty incurred (226,196)
Warranty reserve, December 31, 2020 164,800 
Warranty provision for units sold 119,752 
Costs of warranty incurred (119,752)
Warranty reserve, December 31, 2021 $ 164,800