Note 7 - Agreements, Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Schedule of Product Warranty Liability [Table Text Block]

	2019
Balance at December 31, 2018	$	432,225
Warranty costs charged to cost of goods sold		707,079
Utilization charges against reserve		(315,556	)
Release of accrual related to expired warranties		-
Foreign currency effect		(10,460	)
Balance at December 31 , 2019	$	813,288