We record a write-down, if necessary, to reduce the carrying value of inventory to its net realizable value. The effect of these write-downs is to establish a new cost basis in the related inventory, which we do not subsequently write up. We also record a liability and charge to cost of revenue for estimated losses on inventory we are obligated to purchase from our contract manufacturers when such losses become probable from customer delays, order cancellations, or other factors. The following factors influence our estimates: changes to or cancellations of customer orders, unexpected or sudden decline in demand, rapid product improvements, technological advances, and termination or changes by our original equipment manufacturers, or OEM, customers of any product offerings incorporating our product solutions.