STOCKBASED COMPENSATION (Details Narrative) - USD ($)	3 Months Ended		6 Months Ended
	Nov. 30, 2022	Nov. 30, 2021	Nov. 30, 2022	Nov. 30, 2021
Total intrinsic values of options exercised	$ 2,592,000	$ 9,133,000	$ 3,356,000	$ 11,035,000
Stock Based Compensation Costs Capitalized As part of inventory	$ 101,000		$ 101,000
Weighted average remaining contractual life of the options exercisable and expected to be exercisable			4 years 7 days	4 years 2 months 19 days
Employee Stock Purchase Plan
ESPP purchase right granted	43,000	103,000	43,000	103,000
ESPP share issued	109,000	75,000	109,000	75,000
Unrecognized stock-based compensation	$ 527,000		$ 527,000
Weighted average period for recognition of costs			1 year
ESPP shares available for issuance	499,000	361,000	499,000	361,000
Stock-based compensation related to the ESPP	$ 216,000	$ 302,000	$ 391,000	$ 406,000
Stock Option and RSU
Stock-based compensation expense related to stock options and RSUs	577,000	$ 416,000	1,112,000	$ 900,000
2016 Equity Incentive Plan
Unrecognized stock-based compensation	3,999,000		$ 3,999,000
Weighted average period for recognition of costs			2 years 2 months 12 days
Estimated forfeitures of unvested stock based awards, amount	$ 10,000		$ 10,000