Note 11 - Product Warranty - Changes in Product Warranty Liability (Details) - USD ($)	3 Months Ended	9 Months Ended
Aug. 31, 2024	Aug. 31, 2023	Aug. 31, 2024	Aug. 31, 2023
Balance	$ 196,668	$ 252,444	$ 295,113	$ 192,301
Provision charged to expense	71,426	114,074	250,102	345,409
Less amounts charged-off	(52,176)	(102,485)	(329,297)	(273,677)
Balance	$ 215,918	$ 264,033	$ 215,918	$ 264,033

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