5. INVENTORIES

Inventory costs include materials, labor and factory overhead. Inventories are stated at the lower of cost or net realizable value, determined on a first-in, first-out basis. Appropriate consideration is given to obsolescence, valuation and other factors in determining net realizable value. Revisions of these estimates could result in the need for adjustments. Inventories, net of reserves, at March 31, 2020 and December 31, 2019 consisted of the following:


	March 31,		December 31,
	2020		2019
Chassis	$	7,721	$	6,561
Raw materials		40,014		39,444
Work in process		17,179		16,520
Finished goods		27,727		25,440
	$	92,641	$	87,965