XML 54 R43.htm IDEA: XBRL DOCUMENT v3.21.2
Note 6 - Agreements and Commitments - Changes in Warranty Obligations (Details) - USD ($)
6 Months Ended 12 Months Ended
Jun. 30, 2021
Dec. 31, 2020
Balance at January 1 $ 1,056,613 $ 813,288
Warranty costs charged to cost of goods sold 51,552 348,241
Utilization charges against reserve (102,455) (199,624)
Release of accrual related to expired warranties 0 0
Foreign currency effect (33,015) 94,708
Balance at the end of the period $ 972,695 $ 1,056,613