4. BALANCE SHEET DETAIL - Intangible assets (Details) - USD ($)	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Gross Carrying Amount	$ 4,890,000	$ 4,890,000
Accumulated Amortization	(2,867,000)	(2,634,000)
Total	2,023,000	2,256,000
Amortization of intangible assets	233,000	233,000	$ 223,000
Product Designs
Gross Carrying Amount	590,000	590,000
Accumulated Amortization	(590,000)	(590,000)
Patents
Gross Carrying Amount	4,220,000	4,220,000
Accumulated Amortization	(2,197,000)	(1,964,000)
Total	2,023,000	2,256,000
Software.
Gross Carrying Amount	80,000	80,000
Accumulated Amortization	$ (80,000)	$ (80,000)