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NOTE 4 — Inventories (Tables)
6 Months Ended
Jun. 30, 2021
Inventory Disclosure [Abstract]  
Inventories
   June 30,  December 31,
   2021  2020
Raw materials and sub-assemblies  $4,429,107   $3,642,377 
Finished goods   396,346    281,104 
Inventory reserves   805,943   727,639
Inventory, net  $4,019,510  $3,195,842