Note 4 - Revenue Recognition - Disaggregation of Revenue (Details) - USD ($)	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Net Sales	$ 18,311,830	$ 21,842,097	[1]
UNITED STATES
Net Sales	15,161,311	15,255,741
Non-US [Member]
Net Sales	$ 3,150,519	$ 6,586,356

[1] As adjusted for change in accounting policy (Note 3)