8. Guarantees

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
	March 30, 2013			March 31, 2012

Balance at beginning of period	$	4,692		$	6,801
Warranty expense accruals		240			1,665
Warranty payments		(1,409	)		(1,739	)
Warranty liability assumed from Ismeca acquisition		1,817			—

Balance at end of period	$	5,340		$	6,727

From time-to-time, during the ordinary course of business, we provide standby letters of credit for certain contingent liabilities under contractual arrangements, including customer contracts. As of March 30, 2013, the maximum potential amount of future payments that Cohu could be required to make under these standby letters of credit was approximately $0.6 million. We have not recorded any liability in connection with these guarantee arrangements beyond that required to appropriately account for the underlying transaction being guaranteed. We do not believe, based on historical experience and information currently available, that it is probable that any amounts will be required to be paid under these arrangements.