(5) 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,
		2018		2017
Raw materials	$	58,341	$	47,588
Work-in-progress		5,395		5,806
Finished goods		23,019		20,077
Total inventories, net	$	86,755	$	73,471

Inventory valued using the FIFO method was $69,817 and $54,837 at September 30, 2018 and December 31, 2017, respectively. Inventory valued using the average cost method was $16,938 and $18,634 at September 30, 2018 and December 31, 2017, respectively.