Note 8 - Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2021

Notes Tables

Schedule of Product Warranty Liability [Table Text Block]

Balance at December 31, 2020	$	154,000
Warranties issued during the period		6,000
Settlements made during the period		(66,000	)
Changes in liability for pre-existing warranties during the period		12,000
Balance at March 31, 2021	$	106,000