Some products have a core charge associated with them. A core is some portion of a part that can be recycled or reused by the manufacturer. Doing this saves the manufacturer money and helps our environment. For this reason a product with a core has an additional charge associated with it. If the old part is returned in reusable condition, the core charge will be credited back to the card used to purchase the part. Please note: It is the customer's responsibility to pay any shipping cost associated with shipping a core back to OReillyAuto.com.