Note 10 - Concentration of Credit Risk (Tables)

9 Months Ended

Sep. 30, 2019

Notes Tables

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

	Three Months Ended				Three Months Ended
	September 30, 2019				September 30, 2018
Customer	Net Sales		% of Net Sales		Net Sales		% of Net Sales
Customer A	$	1,799,000		22%	$	2,395,000		24%
Customer B	$	1,559,000		19%	$	2,686,000		27%

	Nine Months Ended				Nine Months Ended
	September 30, 2019				September 30, 2018
Customer	Net Sales		% of Net Sales		Net Sales		% of Net Sales
Customer A	$	8,136,000		27%	$	9,738,000		27%
Customer B	$	8,424,000		28%	$	10,796,000		30%