5. PRODUCT WARRANTIES (Details) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2016	May 31, 2015
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at the beginning of the year	$ 137	$ 223
Accruals for warranties issued during the year	334	150
Settlement made during the year (in cash or in kind)	(316)	(236)
Balance at the end of the year	$ 155	$ 137