CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($)	Nov. 30, 2021	May 31, 2021
Current Assets:
Cash and cash equivalents	$ 7,199,172	$ 4,199,311
Accounts receivable, less allowance for doubtful accounts of $27,777 and $837,415 as of November 30, 2021 and May 31, 2021, respectively	1,125,239	1,455,051
Inventories, net	2,982,201	3,206,255
Prepaid expenses and other	1,096,750	370,290
Total current assets	12,403,362	9,230,907
Property and equipment, net of accumulated depreciation and amortization of $2,026,764 and $1,972,357 as of November 30, 2021 and May 31, 2021, respectively	274,325	310,520
Right of use assets, net of accumulated amortization of $595,116 and $469,077 as of November 30, 2021 and May 31, 2021, respectively	1,427,042	1,553,081
Investments	165,324	165,324
Intangible assets, net of accumulated amortization of $91,030 and $126,769 as of November 30, 2021 and May 31, 2021, respectively	389,486	294,830
Other assets	149,581	264,151
Total Assets	14,809,120	11,818,813
Current Liabilities:
Accounts payable and accrued expenses	1,580,707	583,380
Accrued compensation	674,327	388,896
Advance from customers	2,150,466
Lease liability, current portion	335,385	327,944
Total current liabilities	4,740,885	1,300,220
Lease liability, net of current portion	1,166,808	1,291,570
Total Liabilities	5,907,693	2,591,790
Commitments and contingencies (Notes 1 and 6)
Shareholders' Equity:
Preferred stock, Series A 5% convertible, $0.08 par value, 571,429 shares authorized, none issued and outstanding as of November 30, 2021 and May 31, 2021
Preferred stock, undesignated, no par value, 4,428,571 shares authorized, none issued and outstanding as of November 30, 2021 and May 31, 2021
Common stock, $0.08 par value, 25,000,000 shares authorized, 12,692,327 and 12,307,157 issued and outstanding at November 30, 2021 and May 31, 2021, respectively	1,015,385	984,571
Additional paid-in-capital	41,158,551	38,836,743
Accumulated other comprehensive loss	(58,319)	(47,956)
Accumulated deficit	(33,214,190)	(30,546,335)
Total Shareholders' Equity	8,901,427	9,227,023
Total Liabilities and Shareholders' Equity	14,809,120	11,818,813
5% Convertible Preferred Stock [Member] | Series A Preferred Stock [Member]
Shareholders' Equity:
Preferred stock, Series A 5% convertible, $0.08 par value, 571,429 shares authorized, none issued and outstanding as of November 30, 2021 and May 31, 2021
Preferred stock, undesignated, no par value, 4,428,571 shares authorized, none issued and outstanding as of November 30, 2021 and May 31, 2021