Property and Equipment

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Abstract]

Property and Equipment

6. Property and Equipment

Property and equipment, net consisted of the following:

		December 31,
	Useful Life	2021		2020
Research and development equipment	5 years	$	1,425	$	1,397
Office and computer equipment	3 years		762		733
Autos	5 years		54		54
Furniture and fixtures	7 years		41		41
Leasehold improvements	*		112		283
Construction in progress			45		115
			2,439		2,623
Less accumulated depreciation and amortization			2,105		2,085
Total property and equipment		$	334	$	538

* Shorter of lease term or estimated useful life

(1) For the years ended December 31, 2021 and December 31, 2020, we received net proceeds of $1 and $47 in the sale of research and development equipment and office and computer equipment, respectively, resulting in gains on the sale of these assets of $0 and $21 for the years ended December 31, 2021 and December 31, 2020,  respectively.

Depreciation and amortization expense was approximately $303 and $288 for the years ended December 31, 2021 and 2020, respectively.