REVENUE (Details 1) - USD ($)	3 Months Ended		6 Months Ended
	Nov. 30, 2021	Nov. 30, 2020	Nov. 30, 2021	Nov. 30, 2020
Net sales	$ 9,611,000	$ 1,683,000	$ 15,257,000	$ 3,695,000
United States
Net sales	895,000	970,000	1,401,000	2,011,000
Asia
Net sales	8,716,000	632,000	13,853,000	1,601,000
Europe
Net sales	$ 0	$ 81,000	$ 3,000	$ 83,000