Note 10 - Concentration of Credit Risk (Tables)

6 Months Ended

Jun. 30, 2021

Notes Tables

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

	Three Months Ended					Three Months Ended
	June 30, 2021					June 30, 2020
Customer	Net Sales		% of Net Sales			Net Sales		% of Net Sales
Customer A	$	3,421,000		54	%	$	2,508,000		43	%
Customer B	$	812,000		13	%	$	947,000		16	%

	Six Months Ended					Six Months Ended
	June 30, 2021					June 30, 2020
Customer	Net Sales		% of Net Sales			Net Sales		% of Net Sales
Customer A	$	7,344,000		53	%	$	5,675,000		44	%
Customer B	$	2,106,000		15	%	$	2,110,000		17	%