This 2004-2005 Polaris 900 twin snowmobile cylinder is re-plated to stock specs with a lifetime plating warranty by Millennium, and has the casting number 3021615, which is the same as 3021576. There is no core exchange required for this cylinder. Shipping is only in the lower 48; unless you are purchasing through eBay's Global Shipping Program. If you are in Alaska please contact me before purchasing to check on shipping options. Thanks, -Paul