GEOGRAPHIC INFORMATION (Details) - Geographic information regarding net sales - USD ($)	3 Months Ended		9 Months Ended
	Feb. 28, 2023	Feb. 28, 2022	Feb. 28, 2023	Feb. 28, 2022
Revenues from sales to unaffiliated customers:
Net Sales	$ 1,112,000	$ 7,660,000	$ 4,231,000	$ 13,569,000
Asia [Member]
Revenues from sales to unaffiliated customers:
Net Sales	345,000	4,877,000	1,822,000	8,925,000
Europe [Member]
Revenues from sales to unaffiliated customers:
Net Sales	301,000	2,416,000	1,268,000	3,683,000
North America [Member]
Revenues from sales to unaffiliated customers:
Net Sales	461,000	286,000	1,130,000	820,000
South America [Member]
Revenues from sales to unaffiliated customers:
Net Sales	5,000	81,000	11,000	87,000
Middle East [Member]
Revenues from sales to unaffiliated customers:
Net Sales				$ 54,000