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SIGNIFICANT ACCOUNTING POLICIES (Details) - Inventories - USD ($)
Nov. 30, 2020
May 31, 2020
Inventories [Abstract]    
Raw materials $ 1,748,000 $ 1,635,000
Work in progress 1,516,000 988,000
Finished products 934,000 228,000
Total $ 4,198,213 $ 2,850,836