Summary of significant accounting policies (Tables)

3 Months Ended

Mar. 31, 2015

Summary of significant accounting policies

Schedule of inventories

	March 31, 2015		December 31, 2014
Raw materials and supplies	$	123,569	$	40,749
Work-in process	113,540		135,625
Finished goods	83,698		193,368
Total	$	320,807	$	369,742

Schedule of accrued warranty reserve, reserve expense and cost of replacement parts

	March 31, 2015			December 31, 2014
Balance at beginning of period and year	$	2,750		$	6,500
Warranty expense	750			4,077
Cost of replacement parts and related delivery	(1,500		)	(7,827		)
Balance at end of period and year	$	2,000		$	2,750