(4) Inventories

Inventories are valued at the lower of cost (using either the first-in, first-out (“FIFO”) or average cost methods) or net realizable value. The Company evaluates and adjusts as necessary its excess and obsolescence reserve on a quarterly basis. Excess inventories are quantities of items that exceed anticipated sales or usage for a reasonable period. The Company has guidelines for calculating provisions for excess inventories based on the number of months of inventories on-hand compared to anticipated sales or usage. Management uses its judgment to forecast sales or usage and to determine what constitutes a reasonable period. Inventory cost includes material, labor and overhead. Inventories consisted of the following:


		September 30,		December 31,
		2017		2016
Raw materials	$	47,840	$	35,665
Work-in-progress		8,249		7,483
Finished goods		22,554		16,969
Total inventories, net	$	78,643	$	60,117

Inventory valued using the FIFO method was $56,861 and $37,765 at September 30, 2017 and December 31, 2016, respectively. Inventory valued using the average cost method was $21,782 and $22,352 at September 30, 2017 and December 31, 2016, respectively.