Note 5 - Revenue Recognition - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Net Sales	$ 5,410,762	$ 5,784,839	[1]
UNITED STATES
Net Sales	4,504,275	3,770,884
Non-US [Member]
Net Sales	$ 906,487	$ 2,013,955

[1] As adjusted for change in accounting principle (Note 2)