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Significant Accounting Policies (Details) - Inventories - USD ($)
Feb. 29, 2020
May 31, 2019
Inventories [Abstract]    
Raw materials $ 1,102,000 $ 1,208,000
Work in progress 900,000 771,000
Finished products 186,000 172,000
Total $ 2,187,605 $ 2,151,090