Note 11 - Product Warranty - Changes in Product Warranty Liability (Details) - USD ($)	3 Months Ended	6 Months Ended
May 31, 2025	May 31, 2024	May 31, 2025	May 31, 2024
Balance	$ 190,831	$ 211,121	$ 225,186	$ 295,113
Provision charged to expense	98,336	94,940	183,376	178,676
Less amounts charged-off	(75,238)	(109,393)	(194,633)	(277,121)
Balance	$ 213,929	$ 196,668	$ 213,929	$ 196,668

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://www.xbrl.org/2009/role/commonPracticeRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482425/460-10-50-8

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Subparagraph (c)(5)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482425/460-10-50-8

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