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SIGNIFICANT ACCOUNTING POLICIES (Details) - Inventories - USD ($)
Aug. 31, 2021
May 31, 2021
Inventories [Abstract]    
Raw materials $ 1,493,000 $ 1,583,000
Work in progress 926,000 1,006,000
Finished products 443,000 617,000
Total $ 2,861,779 $ 3,206,255