Nature of Business and Summary of Significant Accounting Policies - Schedule of Property and Equipment (Details) - USD ($)	12 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
Total	$ 4,459,000	$ 4,301,000
Accumulated depreciation	(3,720,000)	(3,545,000)
Net	739,000	756,000
Dies, Jigs, and Molds [Member]
Total	$ 1,808,000	1,685,000
Dies, Jigs, and Molds [Member] | Minimum [Member]
Useful Life in Years	3 years
Dies, Jigs, and Molds [Member] | Maximum [Member]
Useful Life in Years	7 years
Machinery and Equipment [Member]
Total	$ 1,195,000	1,156,000
Machinery and Equipment [Member] | Minimum [Member]
Useful Life in Years	5 years
Machinery and Equipment [Member] | Maximum [Member]
Useful Life in Years	10 years
Furniture and Fixtures [Member]
Total	$ 145,000	145,000
Furniture and Fixtures [Member] | Minimum [Member]
Useful Life in Years	5 years
Furniture and Fixtures [Member] | Maximum [Member]
Useful Life in Years	10 years
Leasehold Improvements [Member]
Total	$ 220,000	214,000
Leasehold Improvements [Member] | Minimum [Member]
Useful Life in Years	5 years
Leasehold Improvements [Member] | Maximum [Member]
Useful Life in Years	32 years
Buildings [Member]
Total	$ 659,000	659,000
Buildings [Member] | Minimum [Member]
Useful Life in Years	20 years
Buildings [Member] | Maximum [Member]
Useful Life in Years	39 years
Automotive [Member]
Total	$ 66,000	76,000
Automotive [Member] | Minimum [Member]
Useful Life in Years	3 years
Automotive [Member] | Maximum [Member]
Useful Life in Years	5 years
Software [Member]
Total	$ 353,000	353,000
Software [Member] | Minimum [Member]
Useful Life in Years	2 years
Software [Member] | Maximum [Member]
Useful Life in Years	5 years
Land [Member]
Total	$ 13,000	$ 13,000
Useful Life in Years	0 years