GEOGRAPHIC INFORMATION (Details) - Geographic information regarding net sales - USD ($)	3 Months Ended		6 Months Ended
	Nov. 30, 2021	Nov. 30, 2020	Nov. 30, 2021	Nov. 30, 2020
Revenues from sales to unaffiliated customers:
Net Sales	$ 4,646,900	$ 1,372,526	$ 5,908,687	$ 2,516,332
Asia [Member]
Revenues from sales to unaffiliated customers:
Net Sales	3,373,000	550,000	4,048,000	897,000
Europe [Member]
Revenues from sales to unaffiliated customers:
Net Sales	796,000	580,000	1,267,000	1,171,000
North America [Member]
Revenues from sales to unaffiliated customers:
Net Sales	429,000	107,000	534,000	241,000
Middle East [Member]
Revenues from sales to unaffiliated customers:
Net Sales	46,000	96,000	54,000	125,000
South America [Member]
Revenues from sales to unaffiliated customers:
Net Sales	$ 3,000	$ 40,000	$ 6,000	$ 82,000