v3.26.1
4. BALANCE SHEET DETAIL - Intangible assets (Details) - USD ($)
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Finite-Lived Intangible Assets [Line Items]      
Gross Carrying Amount $ 4,890,000 $ 4,890,000  
Accumulated Amortization (3,801,000) (3,567,000)  
Total 1,089,000 1,323,000  
Amortization of intangible assets 234,000 233,000 $ 234,000
Product Designs      
Finite-Lived Intangible Assets [Line Items]      
Gross Carrying Amount 590,000 590,000  
Accumulated Amortization (590,000) (590,000)  
Patents      
Finite-Lived Intangible Assets [Line Items]      
Gross Carrying Amount 4,220,000 4,220,000  
Accumulated Amortization (3,131,000) (2,897,000)  
Total 1,089,000 1,323,000  
Software.      
Finite-Lived Intangible Assets [Line Items]      
Gross Carrying Amount 80,000 80,000  
Accumulated Amortization $ (80,000) $ (80,000)