Note 5 - Revenue Recognition - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended			6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2019	Dec. 31, 2018
Net Sales	$ 4,162,659	$ 5,411,227	[1]	$ 9,573,421	$ 11,196,066	[1]
UNITED STATES
Net Sales	3,081,853	3,172,401		7,585,159	7,006,267
Non-US [Member]
Net Sales	$ 1,080,806	$ 2,238,826		$ 1,988,262	$ 4,189,799

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