Listing is for new replacement Thule T2 Pro XT rails.  They will fit either the 9034XT (2" receiver) or 9035XT (1.25" receiver) racks.  The T2 Pro XT is the rack that was just released in January 2017 as the redesign of the T2 Pro so the rack actually fits two fat bikes as it was marketed.  The rails are the component that the bike actually sits on.  These are brand new replacement parts.  If you have the original T2 Pro (9034 or 9035), these rails will fit, but are aesthetically different from the non-XT rails.  The loading arm on the XT rack is now black regardless of which rack colour you have (black or silver) and there is more side to side movement added via the bolt slots.  The colour of the rail itself determines what colour the rack is, so make sure you order the correct one or else it won't match what you already have.  MSRP is $100 plus tax, so if you happen to need one of these, it's probably the best deal you'll find.