| 5. Condensed Consolidated Balance Sheets (Details - Inventories) - USD ($) | Dec. 31, 2020 | Mar. 31, 2020 | 
|---|---|---|
| Inventories Details | ||
| Raw materials, net | $ 1,843,000 | $ 1,128,000 | 
| Finished goods, net | 1,115,000 | 1,064,000 | 
| Inventories, net | $ 2,958,000 | $ 2,192,000 | 
| X | ||||||||||
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- References No definition available. 
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| X | ||||||||||
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- Definition Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of merchandise or goods held by the company that are readily available for sale. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
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- Definition Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
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- Definition Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of unprocessed items to be consumed in the manufacturing or production process. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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