CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (UNAUDITED) - USD ($)	3 Months Ended		6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015
Net sales	$ 1,432,206	$ 1,165,080	$ 2,842,317	$ 2,452,073
Cost of sales	(875,522)	(753,039)	(1,708,666)	(1,618,611)
Gross profit	556,684	412,041	1,133,651	833,462
Operating Expenses:
Selling, general and administrative	475,257	391,603	893,906	731,263
Research and development	300,963	230,212	525,208	388,206
Total operating expenses	776,220	621,815	1,419,114	1,119,469
Loss from operations	(219,536)	(209,774)	(285,463)	(286,007)
Other Income (Expense):
Dividend and interest income	16,829	14,024	27,043	17,958
Interest expense	(180)	(18)	(180)	(54)
Total other income	16,649	14,006	26,863	17,904
Loss before income tax	(202,887)	(195,768)	(258,600)	(268,103)
Income tax benefit		(129,000)		(129,000)
Net loss	$ (202,887)	$ (66,768)	$ (258,600)	$ (139,103)
Basic net loss per common share (in Dollars per share)	$ (0.02)	$ (0.01)	$ (0.03)	$ (0.02)
Diluted net loss per common share (in Dollars per share)	$ (0.02)	$ (0.01)	$ (0.03)	$ (0.02)
Weighted average number of common and common equivalent shares:
Basic (in Shares)	8,189,066	7,586,635	8,208,672	7,584,333
Diluted (in Shares)	8,189,066	7,586,635	8,208,672	7,584,333
Net loss	$ (202,887)	$ (66,768)	$ (258,600)	$ (139,103)
Other comprehensive loss, net of tax:
Foreign currency translation	(786)	(1,023)	(760)	(1,366)
Comprehensive loss	$ (203,673)	$ (67,791)	$ (259,360)	$ (140,469)