Financial Statement Details

Short-term investments

The Company acquired certain short-term investments in trading securities through its acquisition of Ctrack. The Company recognized a gain of approximately $0.2 million and $0.1 million on such securities during the years ended December 31, 2016 and 2015, respectively, which is included in other income (expense), net, in the consolidated statements of operations. The Company did not have short-term investments during the year ended December 31, 2017.

Inventories

Inventories consist of the following (in thousands):



	December 31,
	2017		2016
Finished goods	$	14,331	$	19,277
Raw materials and components	6,072		11,865
	$	20,403	$	31,142

Property, Plant and Equipment

Property, plant and equipment consists of the following (in thousands):



	December 31,
	2017			2016
Land	$	288		$	260
Buildings	2,614			2,363
Test equipment	23,396			23,115
Computer equipment and purchased software	5,548			4,373
Product tooling	449			409
Furniture and fixtures	564			915
Vehicles	2,003			1,746
Leasehold improvements	267			243
	35,129			33,424
Less—accumulated depreciation and amortization	(28,138		)	(25,032		)
	$	6,991		$	8,392

At December 31, 2017, the Company had vehicles and equipment under capital leases of $1.6 million, net of accumulated amortization of $1.5 million. At December 31, 2016, the Company had vehicles and equipment under capital leases of $1.8 million, net of accumulated amortization of $1.1 million.

Rental Assets

Rental assets consist of the following (in thousands):



	December 31,
	2017			2016
Rental assets	$	16,602		$	11,115
Less—accumulated depreciation	(9,039		)	(4,112		)
	$	7,563		$	7,003

Depreciation and amortization expense related to property, plant and equipment, including equipment under capital leases, and rental assets was $8.0 million, $7.8 million and $5.0 million for the years ended December 31, 2017, 2016 and 2015, respectively.

Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consist of the following (in thousands):



	December 31,
	2017		2016
Royalties	$	1,558	$	1,544
Payroll and related expenses	2,870		5,315
Warranty obligations	400		480
Market development funds and price protection	34		320
Professional fees	1,789		4,793
Bank overdrafts	117		489
Accrued interest	239		275
Deferred revenue	1,823		1,656
Restructuring	964		837
Acquisition-related liabilities	13,186		7,912
Divestiture-related liabilities	—		463
Other	4,578		3,813
	$	27,558	$	27,897