SEGMENT INFORMATION (Details Narrative) - USD ($)	3 Months Ended		6 Months Ended
	Nov. 30, 2021	Nov. 30, 2020	Nov. 30, 2021	Nov. 30, 2020	May 31, 2021
Operating lease right-of-use assets	$ 1,265,000		$ 1,265,000		$ 1,606,000
United States [Member]
Operating lease right-of-use assets	1,156,000		1,156,000
Asia [Member]
Operating lease right-of-use assets	$ 109,000		$ 109,000
Five Largest Customers [Member]
Customers accounted for 10% or more of total revenues	98.00%	90.00%	96.00%	74.00%
Customer A [Member]
Customers accounted for 10% or more of total revenues		22.00%		20.00%
Customer E [Member]
Customers accounted for 10% or more of total revenues		15.00%		10.00%
Customers B [Member]
Customers accounted for 10% or more of total revenues		18.00%		18.00%
Customers C [Member]
Customers accounted for 10% or more of total revenues		18.00%		15.00%
Customers D [Member]
Customers accounted for 10% or more of total revenues		16.00%		11.00%
Customer One [Member]
Customers accounted for 10% or more of total revenues	82.00%		77.00%