BALANCE SHEET COMPONENTS

Accounts Receivable, Net

Accounts receivable are recorded at invoiced amount and do not bear interest when recorded or accrue interest when past due. Accounts receivable are stated net of an allowance for doubtful accounts, which is maintained for estimated losses that may result from the inability of our customers to make required payments.

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

Inventories consist of finished goods and work-in-process, and are stated at the lower of standard cost (which approximates actual cost on a first-in, first-out basis) or market (net realizable value).

Inventories consist of the following:



	June 30, 2015		December 31, 2014
Finished goods	$	2,098	$	1,697
Work-in-process	777		1,201
Inventories	$	2,875	$	2,898

Property and Equipment, Net

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

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

Short-Term Line of Credit

On December 21, 2010, we entered into a Loan and Security Agreement (the "Revolving Loan Agreement") with Silicon Valley Bank (the "Bank"). On December 14, 2012, we and the Bank entered into Amendment No. 1 to the Revolving Loan Agreement (the "Amendment No. 1"). The Revolving Loan Agreement, as amended, provides a secured working capital-based revolving line of credit (the "Revolving Line") in an aggregate amount of up to the lesser of (i) $10,000, or (ii) $1,000 plus 80% of eligible domestic accounts receivable and certain foreign accounts receivable. On December 4, 2013, we and the Bank entered into Amendment No. 2 (the "Amendment No. 2") to the Revolving Loan Agreement which changes the maturity date of the Revolving Line to January 1, 2016. The maturity date was previously December 14, 2014, as provided by Amendment No. 1. In addition, the Revolving Loan Agreement, as amended, provides for non-formula advances of up to $10,000 which may be made solely during the last five business days of any fiscal month or quarter and which must be repaid by the Company on or before the fifth business day after the applicable fiscal month or quarter end. Due to their repayment terms, non-formula advances do not provide the Company with usable liquidity.

The Revolving Loan Agreement, as amended, contains customary affirmative and negative covenants as well as customary events of default. The occurrence of an event of default could result in the acceleration of the Company's obligations under the Revolving Loan Agreement, as amended, and an increase to the applicable interest rate, and would permit the Bank to exercise remedies with respect to its security interest. As of June 30, 2015, we were in compliance with all of the terms of the Revolving Loan Agreement, as amended.

Short-term borrowings outstanding under the Revolving Line consisted of non-formula advances of $3,000 as of June 30, 2015 and as of December 31, 2014, both advances were repaid within required terms. The weighted-average interest rate on short-term borrowings outstanding as of June 30, 2015 and December 31, 2014 was 3.5%.