XML 42 R22.htm IDEA: XBRL DOCUMENT v3.20.1
Note 5 - Agreements and Commitments (Tables)
3 Months Ended
Mar. 31, 2020
Notes Tables  
Schedule of Product Warranty Liability [Table Text Block]
   
March 31,
2020
   
December 31,
2019
 
Balance at December 31
  $
813,288
    $
432,225
 
Warranty costs charged to cost of goods sold
   
226,079
     
707,079
 
Utilization charges against reserve
   
(51,643
)
   
(315,556
)
Release of accrual related to expired warranties
   
-
     
-
 
Foreign currency effect
   
(17,679
)
   
(10,460
)
Balance at March 31
  $
970,045
    $
813,288