5. PRODUCT WARRANTIES (Details) - USD ($) $ in Thousands	12 Months Ended
	May. 31, 2015	May. 31, 2014
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at the beginning of the year	$ 223	$ 222
Accruals for warranties issued during the year	150	297
Settlement made during the year (in cash or in kind)	(236)	(296)
Balance at the end of the year	$ 137	$ 223