Note 9 - Concentration of Credit Risk (Tables)

3 Months Ended

Mar. 31, 2019

Notes Tables

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

	Three Months Ended					Three Months Ended
	March 31, 201 9					March 31, 201 8
Customer	Net Sales		% of Net Sales			Net Sales		% of Net Sales
Customer A	$	3,861,000		30.8	%	$	4,450,000		31.8	%
Customer B	$	2,159,000		17.2	%	$	2,471,000		17.7	%