NOTE 6 ACCRUED WARRANTY

The following table details the change in the accrued warranty balance (in thousands):

We generally warrant our products against defects for 1 to 3 years. A provision for estimated future costs and estimated returns for credit relating to warranty is recorded when products are shipped and revenue recognized. Our estimate of future costs to satisfy warranty obligations is primarily based on historical trends and, if believed to be significantly different from historical trends, estimates of future failure rates and future costs of repair including materials consumed in the repair, labor and overhead amounts necessary to perform the repair. If future actual failure rates differ from our estimates, we record the impact in subsequent periods. If future actual costs to repair were to differ significantly from our estimates, we record the impact of these unforeseen cost differences in subsequent periods.