Engineered as integrated, interdependent transmission components, the T-Type derailleur mounts around the wheel axle itself, contacting the cassette directly with a first-of-its-kind Hangerless Interface. The Full Mount attachment method creates a far stronger connection and grips both sides of the frame. It features an overload clutch and a tucked-in profile. Magic Wheel lower pulley keeps spinning if an object becomes lodged. Hangerless Interface, Full Mount attachment method (UDH compatible frame required) Battery Not Included SRAM Model ID: RD-XX-SLE-B1 TECH SPECS Maximum Cog 52T Primary Color Black Minimum Cog 10T Speed 12