Balance Sheet Components (Tables)

Accounts receivable consists of the following:



	June 30, 2015			December 31, 2014
Accounts receivable, gross	$	4,964		$	4,949
Less: allowance for doubtful accounts	(231		)	(301		)
Accounts receivable, net	$	4,733		$	4,648

The following is the change in our allowance for doubtful accounts:



	Six Months Ended
	June 30,
	2015			2014
Balance at beginning of period	$	301		$	315
Reductions credited	(4		)	(5		)
Accounts written-off, net of recoveries	(66		)	—
Balance at end of period	$	231		$	310

Inventories consist of the following:

Property and equipment consists of the following:



	June 30, 2015			December 31, 2014
Gross carrying amount	$	29,853		$	27,573
Less: accumulated depreciation and amortization	(22,823		)	(21,171		)
Property and equipment, net	$	7,030		$	6,402

Accrued liabilities and current portion of long-term liabilities consist of the following:



	June 30, 2015		December 31, 2014
Accrued payroll and related liabilities	$	2,891	$	2,385
Accrued commissions and royalties	2,194		2,055
Accrued interest payable	1,537		1,383
Current portion of accrued liabilities for asset financings	967		1,744
Deferred revenue	153		30
Reserve for warranty returns	32		105
Other	1,411		837
Accrued liabilities and current portion of long-term liabilities	$	9,185	$	8,539

The following is the change in our reserve for warranty returns:



	Six Months Ended
	June 30,
	2015			2014
Reserve for warranty returns:
Balance at beginning of period	$	105		$	329
Benefit	(65		)	(53		)
Charge-offs	(8		)	(22		)
Balance at end of period	$	32		$	254