CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (UNAUDITED) - USD ($)	3 Months Ended		9 Months Ended
	Feb. 29, 2020	Feb. 28, 2019	Feb. 29, 2020	Feb. 28, 2019
Net sales	$ 1,176,889	$ 1,261,161	$ 3,967,712	$ 4,034,822
Cost of sales	(964,910)	(895,237)	(2,919,557)	(2,923,615)
Gross profit	211,979	365,924	1,048,155	1,111,207
Operating Expense:
Selling, general and administrative	653,585	576,070	1,714,543	1,488,890
Research and development	473,279	497,102	1,248,599	1,270,288
Total operating expenses	1,126,864	1,073,172	2,963,142	2,759,178
Loss from operations	(914,885)	(707,248)	(1,914,987)	(1,647,971)
Other Income (Expense):
Dividend and interest income	53,964	28,502	62,515	40,288
Interest expense	(5)		(10)	(47)
Total other income	53,959	28,502	62,505	40,241
Net loss	$ (860,926)	$ (678,746)	$ (1,852,482)	$ (1,607,730)
Basic net loss per common share (in Dollars per share)	$ (0.09)	$ (0.07)	$ (0.19)	$ (0.18)
Diluted net loss per common share (in Dollars per share)	$ (0.09)	$ (0.07)	$ (0.19)	$ (0.18)
Weighted average number of common and common equivalent shares:
Basic (in Shares)	9,814,504	9,322,549	9,882,459	9,103,225
Diluted (in Shares)	9,814,504	9,322,549	9,882,459	9,103,225
Net loss	$ (860,926)	$ (678,746)	$ (1,852,482)	$ (1,607,730)
Other comprehensive loss, net of tax:
Foreign currency translation	(928)	(1,579)	(4,157)	(7,385)
Comprehensive loss	$ (861,854)	$ (680,325)	$ (1,856,639)	$ (1,615,115)