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The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of valuation reserve for inventory.

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Amount of cash inflow from exercise of stock options granted under share-based compensation arrangement.

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Amount of estimated sales returns.

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Gross number of share options (or share units) granted during the period.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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Number of share options (or share units) exercised during the current period.

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Threshold period past due for trade accounts receivable to write off as uncollectible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Significant Accounting Policies (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
Significant Accounting Policies (Details) - USD ($)	Nov. 30, 2018	Nov. 30, 2017	Nov. 30, 2018	Nov. 30, 2017	May 31, 2018
Significant Accounting Policies (Details) [Line Items]
Threshold Period Past Due for Write-off of Trade Accounts Receivable			90 days
Inventory Valuation Reserves	$ 79,000		$ 79,000		$ 52,000
Depreciation, Depletion and Amortization	28,387	$ 27,913	55,682	$ 59,135
Amortization of Intangible Assets	16,665	$ 17,387	$ 33,331	34,998
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in Shares)			98,500
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit (in Dollars per share)			$ 0.71
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit (in Dollars per share)			$ 1.04
Proceeds from Stock Options Exercised			$ 75,200	$ 13,789
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in Shares)			139,000	139,000
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in Dollars per share)			$ 3.62	$ 3.62
Revenue Recognition, Sales Returns, Reserve for Sales Returns			$ 0		0
Deferred Tax Assets, Valuation Allowance	$ 1,740,000		$ 1,740,000		$ 1,549,000
Employee Stock Option [Member]
Significant Accounting Policies (Details) [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in Shares)	509,101	604,118	534,551	551,208
Minimum [Member]
Significant Accounting Policies (Details) [Line Items]
Property, Plant and Equipment, Useful Life			5 years
Maximum [Member]
Significant Accounting Policies (Details) [Line Items]
Property, Plant and Equipment, Useful Life			10 years
Investment In Polish Distributor [Member]
Significant Accounting Policies (Details) [Line Items]
Equity Method Investment, Ownership Percentage	6.00%		6.00%
Marketing-Related Intangible Assets [Member] \| Maximum [Member]
Significant Accounting Policies (Details) [Line Items]
Finite-Lived Intangible Asset, Useful Life			18 years
Purchased Technology Rights [Member] \| Maximum [Member]
Significant Accounting Policies (Details) [Line Items]
Finite-Lived Intangible Asset, Useful Life			10 years
Patents [Member] \| Maximum [Member]
Significant Accounting Policies (Details) [Line Items]
Finite-Lived Intangible Asset, Useful Life			17 years
Credit Concentration Risk [Member] \| Accounts Receivable [Member]
Significant Accounting Policies (Details) [Line Items]
Concentration Risk, Percentage			59.60%		53.30%
Customer Concentration Risk [Member] \| Sales Revenue, Net [Member]
Significant Accounting Policies (Details) [Line Items]
Concentration Risk, Percentage			44.70%	44.60%
Supplier Concentration Risk [Member] \| Cost of Goods, Product Line [Member]
Significant Accounting Policies (Details) [Line Items]
Concentration Risk, Percentage			33.80%	44.20%