Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2015

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment

Property and equipment are stated at cost and depreciated using the straight-line method over the estimated useful lives of the related assets and consist of the following (in thousands):

	At December 31,
	2015			2014
Equipment (useful life 3 - 15 years)	$	2,864		$	1,289
Tooling (useful life 2 - 5 years)	851			851
Vehicles (useful life 5 years)	39			—
Furniture and fixtures (useful life 5 years)	104			85
Computer software (useful life 3 years)	581			378
Leasehold improvements (the shorter of useful life or lease life)	509			509
Construction in progress	310			18
Property and equipment at cost	5,258			3,130
Less: accumulated depreciation	(2,829		)	(2,674		)
Property and equipment, net	$	2,429		$	456