CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (UNAUDITED) - USD ($)	3 Months Ended		6 Months Ended
	Nov. 30, 2015	Nov. 30, 2014	Nov. 30, 2015	Nov. 30, 2014
Net sales	$ 1,165,080	$ 1,133,600	$ 2,452,073	$ 2,168,050
Cost of sales	(753,039)	(826,357)	(1,618,611)	(1,550,896)
Gross profit	412,041	307,243	833,462	617,154
Operating Expenses:
Selling, general and administrative	391,603	375,020	731,263	713,336
Research and development	230,212	182,088	388,206	377,794
Total operating expenses	621,815	557,108	1,119,469	1,091,130
Loss from operations	(209,774)	(249,865)	(286,007)	(473,976)
Other Income (Expense):
Dividend and interest income	14,024	$ 11,837	17,958	16,697
Interest expense	(18)		(54)	(17)
Total other income	14,006	$ 11,837	17,904	16,680
Loss before income tax	(195,768)	$ (238,028)	(268,103)	$ (457,296)
Income tax benefit	(129,000)		(129,000)
Net loss	$ (66,768)	$ (238,028)	$ (139,103)	$ (457,296)
Basic net loss per common share (in Dollars per share)	$ (0.01)	$ (0.03)	$ (0.02)	$ (0.06)
Diluted net loss per common share (in Dollars per share)	$ (0.01)	$ (0.03)	$ (0.02)	$ (0.06)
Weighted average number of common and common equivalent shares:
Basic (in Shares)	7,586,635	7,551,972	7,584,333	7,549,894
Diluted (in Shares)	7,586,635	7,551,972	7,584,333	7,549,894
Net loss	$ (66,768)	$ (238,028)	$ (139,103)	$ (457,296)
Other comprehensive loss, net of tax:
Foreign currency translation	(1,023)	(744)	(1,366)	(1,678)
Comprehensive loss	$ (67,791)	$ (238,772)	$ (140,469)	$ (458,974)