microSHIFT's ADVENT X Ver.2 is the same great derailleur you know and love, but with an all new cage design that improves performance under the hardest riding. The cage features a shorter overall length and improved pulley position for better chain wrap, especially in the smaller cogs. With more tooth engagement on the pulleys, shifting speed and chain retention both improve. And more tooth engagement on the cassette means longer cassette life, especially on the small cogs.