Nature of Business and Summary of Significant Accounting Policies - Income Statement location (Details) - USD ($)	12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2022
Net sales	$ 188,820,000	$ 169,997,000	$ 143,593,000
Cost of sales	87,066,000	96,764,000	84,437,000
Research and development	10,763,000	9,328,000	8,024,000
Selling, General and Administrative Expenses
Advertising and promotion costs	3,262,000	2,931,000	2,889,000
Operating Expenses
Research and development	10,763,000	9,328,000	8,024,000
Cost of sales | Shipping and Handling
Cost of sales	1,573,000	1,697,000	1,425,000
Sales revenue, net | Shipping and Handling
Net sales	$ 349,000	$ 450,000	$ 428,000