CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (UNAUDITED) - USD ($)	3 Months Ended		9 Months Ended
	Feb. 29, 2016	Feb. 28, 2015	Feb. 29, 2016	Feb. 28, 2015
Net sales	$ 1,361,608	$ 1,299,400	$ 3,813,683	$ 3,467,450
Cost of sales	(1,017,090)	(840,568)	(2,635,701)	(2,391,464)
Gross profit	344,518	458,832	1,177,982	1,075,986
Operating Expenses:
Selling, general and administrative	428,356	409,737	1,159,624	1,123,073
Research and development	185,270	184,632	573,473	562,420
Total operating expenses	613,626	594,369	1,733,097	1,685,493
Loss from operations	(269,108)	(135,537)	(555,115)	(609,507)
Other Income (Expense):
Dividend and interest income	9,175	$ 1,724	27,134	18,421
Interest expense	(69)		(124)	(17)
Total other income	9,106	$ 1,724	27,010	18,404
Loss before income tax benefit	(260,002)	(133,813)	(528,105)	(591,103)
Income tax benefit	125,000	16,620	254,000	16,620
Net loss	$ (135,002)	$ (117,193)	$ (274,105)	$ (574,483)
Basic net loss per common share (in Dollars per share)	$ (0.02)	$ (0.02)	$ (0.04)	$ (0.08)
Diluted net loss per common share (in Dollars per share)	$ (0.02)	$ (0.02)	$ (0.04)	$ (0.08)
Weighted average number of common and common equivalent shares:
Basic (in Shares)	7,617,272	7,554,603	7,595,273	7,551,447
Diluted (in Shares)	7,617,272	7,554,603	7,595,273	7,551,447
Net loss	$ (135,002)	$ (117,193)	$ (274,105)	$ (574,483)
Other comprehensive loss, net of tax:
Foreign currency translation	(73)	(308)	(1,439)	(1,987)
Comprehensive loss	$ (135,075)	$ (117,501)	$ (275,544)	$ (576,470)