OPTIONAL Buffalo 3-Year Keep Your Drive Warranty Upgrade for TeraStation 8-Bay Full / 12-Bay Partial Keep Your Drive Warranty Services include hard drive replacement that does not require the return of the defective hard drive, in addition to Next Business Day air service, cross-shipment service, and pre-paid return shipping labels within the length of the warranty.This service can only be purchased at the time of product purchase or within 90 days of purchase.