Note 2 - Reserve for Product Warranty Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Reserve for product warranty, beginning of period	$ 33,500	$ 35,190
Provision for product warranty	434,000	51,210
Product warranty expirations	(33,500)	(52,900)
Product warranty costs paid	(74,346)
Reserve for product warranty, end of period	$ 359,654	$ 33,500