INCOME TAXES (Details 3) - USD ($)	May 31, 2022	May 31, 2021
Deferred tax assets:
Net operating losses	$ 14,912,000	$ 15,584,000
Lease liability	218,000	372,000
Credit carryforwards	5,535,000	5,298,000
Inventory reserves	934,000	1,006,000
Reserves and accruals	1,360,000	890,000
Other	220,000	450,000
Gross deferred tax assets	23,179,000	23,600,000
Deferred tax liabilities:
Operating lease right-of-use assets	(199,000)	(342,000)
Less: Valuation allowance	(22,980,000)	(23,258,000)
Net deferred tax assets (liabilities)	$ 0	$ 0