New/NOS/Unmounted SRAM XO Medium Cage MTB Rear Derailleur.  Deluxe presentation box and original instructions included.  1 to 1 actuation, carbon cage, 195 grams, ball bearing pulleys, forged alloy links.  Buyer to pay $10.00 USPS Ground Advantage Shipping with tracking.  Buyers outside the Continental US to use Ebay's International Shipping service.  Thanks for looking.