[Teeth]: 11/12/13T. [Cog Material]: High tensile steel. The internal thread has high precision, smooth rotation and easy maintenance. [Easy to Install]: Freewheel lightweight and compact. Easy to be removed or installed by freewheel tools. [Compatibility]: Shimano and SRAM transmission system....

[Name]: Extend Tail Hook / Rear Dialing Converter [Weight]: about 11.7g (including screws) [Material]: Made of high quality aluminum alloy and processed by CNC. It is strong, firm, durable and corrosion resistant [Installation]: The screws provided with the extender need to...