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Schedule of Amortization of Patents and Trademarks (Details) - USD ($)
$ in Thousands
Sep. 30, 2021
Dec. 31, 2020
Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]      
2021 $ 17    
2022 140    
2023 163    
2024 185    
2025 215    
Thereafter 1,125    
Total $ 1,845 $ 1,498 $ 1,151