Note 2 - Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

Notes Tables

Schedule of Product Warranty Liability [Table Text Block]

	2015			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

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

2013
	5 year options
Expected Life		6.5
Expected volatility		123.3	%
Risk-free interest rate		0.75	%