Concentration of credit risk (Details) - USD ($)	12 Months Ended
Jun. 30, 2018	Jun. 30, 2017
Concentration Risk [Line Items]
Concentration Risk, Customer	0.1
Concentration Risk, Credit Risk, Financial Instruments	0.11	0.12
Concentration Risk, Supplier	0.41	0.36
Revenue, Net	$ 11,402,272	$ 11,234,868
Sales Revenue, Net [Member] \| Geographic Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue, Net	$ 11,402,000	$ 11,235,000
Concentration Risk, Percentage	100.00%	100.00%
Domestic [Member] \| Sales Revenue, Net [Member] \| Geographic Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue, Net	$ 6,802,000	$ 6,414,000
Concentration Risk, Percentage	59.66%	57.09%
International [Member] \| Sales Revenue, Net [Member] \| Geographic Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue, Net	$ 4,600,000	$ 4,821,000
Concentration Risk, Percentage	40.34%	42.91%

Description of credit risk arising from all financial instruments, whether from an individual counterparty or groups of counterparties. Includes disclosures concerning (a) information about the (shared) activity, region or economic characteristic that identifies the concentration, (b) the maximum amount of loss due to credit risk that would be incurred if the counterparties failed completely to perform according to the terms of the contracts, and any security or collateral for the amount due proved to be of no value, (c) the entity's policy of requiring collateral or other security to support financial instruments subject to credit risk, information about the entity's access to that collateral or other security, and the nature and a brief description of the collateral or other security supporting those financial instruments, and (d) the policy of entering into and information about master netting arrangements to mitigate the credit risk of financial instruments, and a brief description of the terms of those arrangements, including the extent to which they would reduce the maximum amount of loss due to credit risk.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13537-108611

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Description of risks that arise due to the volume of business transacted with a particular customer. At a minimum, the description informs financial statement users of the general nature of the risk, but excludes "Information about Major Customers" that may be disclosed elsewhere (for instance, segment disclosures).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592

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-Publisher FASB
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-Topic 275
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592

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-Publisher FASB
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Description of risks that arise due to the volume of business transacted with a particular supplier or reliance placed on that supplier. At a minimum, the description informs financial statement users of the general nature of the risk.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592

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-Publisher FASB
-Name Accounting Standards Codification
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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
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