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Inventory (Details) - USD ($) | 9 Months Ended |
--- | --- | ---
Sep. 30, 2018 | Sep. 30, 2017 | Dec. 31, 2017
Inventory Disclosure [Abstract] |  |  |
Allowance for inventory obsolescence | $ 20,785 |  | $ 15,000
Raw materials - current | 15,080,000 |  | 22,813,000
Raw materials - long term | 3,815,000 |  | 2,829,000
Finished Goods | 1,022,000 |  | 1,022,000
Work in process | 2,963,000 |  | 2,389,000
Inventory, net | 22,880,000 |  | $ 29,053,000
Write-offs of obsolete inventory against allowance | $ 0 | $ 0 |

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