The Box Two 11sp rear derailleur features a non-adjustable version of the new Tri-Pack clutch technology The Box Two 11sp rear derailleur features a non-adjustable version of the new Tri-Pack clutch technology Patent pending Pivot Tech works to prevent damage in the event of crashes or trail-side impacts through the use of a spring loaded cable stop With a maximum tooth count of 46, the Box One Rear Derailleur can easily handle today`s gear ratios and wide range cassettes The Box Two is made from 6061-T6 Aluminum, Glass fiber and nylon composite for cost effective performance Head and top link are now forged rather than cast for improved strength and performance