SRAM celebrates its 20th anniversary with a revised X.0 rear derailleur, which now features an aluminum inner pulley cage and true carbon fiber outer cage for increased stiffness and durability. The long cage version gets the carbon treatment for the first time, and all X.0 rear derailleurs will receive special graphics treatment, including a gold-anodized and laser-etched B-bolt.

20주년 기념버전 X0 드레일러 나온다고 합니다.
기존의 X0 카본 케이지가 True carbon이 아니었나보네요.