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Geographic Information (Details) - USD ($)
3 Months Ended
Aug. 31, 2018
May 31, 2018
Geographic Information (Details) [Line Items]    
Property, Plant and Equipment, Net $ 361,935 $ 351,149
Geographic Concentration Risk [Member]    
Geographic Information (Details) [Line Items]    
Concentration Risk, Percentage 10.00%  
MEXICO    
Geographic Information (Details) [Line Items]    
Inventory, Gross $ 676,000 657,000
Property, Plant and Equipment, Net $ 43,000 $ 41,000