Inventories

3 Months Ended

Mar. 31, 2020

Notes

Inventories

6.  Inventories are stated at the lower of cost or net realizable value, cost being determined by the first-in, first-out method.

  A summary of inventories is as follows:

	March 31, 2020	December 31, 2019
Raw material	$             2,315,729	$             2,337,278
Work-in-process	1,341,053	1,201,099
Finished goods	2,008,599	1,869,800
Inventory, gross	5,665,381	5,408,177
Valuation reserves	(487,000)	(457,000)
Inventories, net	$             5,178,381	$             4,951,177