Shimano's armor-clad Saint Rear Derailleur uses their low-profile Shadow technology. It protects you precious derailleur in rough rock gardens, overgrown singletrack and in those inevitable crashes. The Saint's skid-plate design shrugs off hits without complaint and the adjustable bump stop eliminates chainstay contact. But don't let its toughness fool you, the Saint still has the smooth action and sniper-like shifting that Shimano is famous for. It's even compatible with tight road cassettes for you serious DHers out there.