Note 3 - Significant Accounting Policies - Reserve for Product Warranty Activity (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Reserve for product warranty, beginning of period	$ 33,500	$ 35,190
Provision for product warranty	136,700	51,210
Product warranty expirations	(23,300)	$ (52,900)
Product warranty costs paid	(7,490)
Reserve for product warranty, end of period	$ 139,410	$ 33,500