8.	Guarantees and Other Obligations

Product Warranty

Our products are generally sold with warranty periods that range from 12 to 36 months following sale or acceptance. Parts and labor are covered under the terms of the warranty agreement. The warranty provision is based on historical and projected experience by product and configuration.

Changes in accrued warranty were as follows

(

in thousands

)

	Three Months Ended						Six Months Ended
	June 25, 2016			June 27, 2015			June 25, 2016			June 27, 2015
Balance at beginning of period	$	5,218		$	5,351		$	4,886		$	5,848
Warranty expense accruals		1,446			1,928			3,266			3,195
Warranty payments		(1,546	)		(2,067	)		(3,034	)		(3,831	)
Balance at end of period	$	5,118		$	5,212		$	5,118		$	5,212

Accrued warranty amounts expected to be incurred after one year are included in noncurrent other accrued liabilities in the condensed consolidated balance sheet. These amounts total $1.0 million at June 25, 2016 and $1.1 million at December 26, 2015.

Standby Letters of Credit

During the ordinary course of business, we provide standby letters of credit instruments to certain parties as required. As of June 25, 2016, no amounts were outstanding under standby lines of credit.

Lines of Credit

One of our wholly owned subsidiaries has two available lines of credit which provide it with borrowings of up to a total of 2.5 million Swiss Francs. At June 25, 2016 and December 26, 2015, no amounts were outstanding under the lines of credit.