Note 9 - Product Warranty - Changes in Product Warranty Liability (Details) - USD ($)	3 Months Ended
Feb. 28, 2023	Feb. 28, 2022
Balance, beginning	$ 193,301	$ 202,850
Settlements / adjustments	115,596	21,624
Warranties issued	(114,433)	(109,412)
Balance, ending	$ 194,464	$ 115,062

Amount as of the balance sheet date of the aggregate standard product warranty liability. Does not include the balance for the extended product warranty liability.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)(1),(c)(5)
-URI https://asc.fasb.org/extlink&oid=126907703&loc=d3e12565-110249

Name:	us-gaap_StandardProductWarrantyAccrual
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant