Property and Equipment

12 Months Ended

Dec. 31, 2021

Property and Equipment

Property and Equipment

5. Property and Equipment

Major classifications of property and equipment and estimated useful lives were as follows:

	Estimated useful lives				As of December 31,
	in years				2021			2020
Office furniture and equipment		3	to	10	$	5,410		$	5,219
Leasehold improvements		2	to	7		1,610			1,610
Vehicles		5	to	10		206			206
Manufacturing and test equipment		2	to	10		2,846			2,833
						10,072			9,868
Accumulated depreciation and amortization						(9,328	)		(8,962	)
Property and equipment, net					$	744		$	906

Depreciation expense on property and equipment for the years ended December 31, 2021 and 2020 was $378 and $422, respectively.