NET SALES BY PRODUCT LINE AND GEOGRAPHY (Details)	12 Months Ended
	Apr. 30, 2018 USD ($) customer	Apr. 30, 2017 USD ($) customer
Revenue from External Customer
Net sales | $	$ 18,396,000	$ 16,302,000
Number of customers for given percentage annual sales volume | customer	19
Annual sales volume percentage	90.00%
Number of major customers for given percentage consolidated net sales | customer	2	2
Number of major customer | customer	1	1
Major Customer One
Revenue from External Customer
Consolidated net sales percentage	34.00%	34.00%
Consolidated net trade receivables	36	27
Major Customer Two
Revenue from External Customer
Consolidated net sales percentage	18.00%	23.00%
Domestic
Revenue from External Customer
Net sales | $	$ 16,236,556	$ 14,755,000
Foreign
Revenue from External Customer
Net sales | $	$ 2,159,444	$ 1,547,000