Inventories, net

Inventories, net consists of the following:


	As of
	June 30,		December 31,
	2019		2018
	(Amounts in thousands)
Raw materials	$	32,373	$	24,937
Work-in-process		5,866		5,185
Finished products		13,036		12,141

Total inventories, net	$	51,275	$	42,263

Property, Plant and Equipment

Property, plant and equipment consist of the following:


	As of
	June 30,			December 31,
	2019			2018
	(Amounts in thousands)
Land	$	1,023		$	1,023
Buildings		764			764
Leasehold improvements		22,936			16,259
Equipment		30,495			24,092
Furniture and fixtures		6,941			5,448
Construction in progress (1)		7,343			12,906
Other		50			—

Total property, plant and equipment		69,552			60,492
Less - Accumulated depreciation		(31,427	)		(28,312	)

Total property, plant and equipment, net	$	38,125		$	32,180

(1)

Construction in progress as of June 30, 2019 includes $5.6 million in capitalized internal-use software development costs and $0.3 million in manufacturing improvements at our Rancho Dominguez facility among other projects. Construction in progress as of December 31, 2018 included $7.3 million for the buildout of our Marlborough facility, which was put into service and began depreciating on January 1, 2019, $2.1 million in capitalized

internal-use

software development costs and $2.1 million for a casting machine, among other projects.

Depreciation expenses totaled $1.8 million and $1.3 million for the three months ended June 30, 2019 and 2018, respectively. Depreciation expenses totaled $3.3 million and $2.6 million for the six months ended June 30, 2019 and 2018, respectively.

Accrued Liabilities

Accrued liabilities consist of the following:


	As of
	June 30,		December 31,
	2019		2018
	(Amounts in thousands)
Employee compensation	$	10,487	$	9,953
Taxes		2,353		1,024
Royalty and license fees		163		242
Accrued purchases		407		683
Warranties		796		546
Professional fees		807		942
Deferred revenue		3,728		1,290
Other		1,877		1,185

Total accrued liabilities	$	20,618	$	15,865