Assets Manufactured for Internal Use, net

12 Months Ended

Dec. 31, 2019

Assets Manufactured for Internal Use, net

Assets Manufactured for Internal Use, net

Note 8. Assets Manufactured for Internal Use, net

Assets manufactured for internal use, included in other assets, are depreciated using the straight-line method over their 10 year estimated useful life. Their components are as follows:


	December 31,
	2019		2018
	(in thousands)
Internal use assets	$	56,775	$	47,509
Construction in process		5,242		1,609
Total cost		62,017		49,118
Accumulated depreciation		(19,259)		(19,285)
Assets manufactured for internal use, net	$	42,758	$	29,833

These products are used for research and development, training, and customer demonstration purposes.

Depreciation expense was $3.9 million, $2.6 million and $2.8 million for the years ended December 31, 2019, 2018 and 2017, respectively.