ใบแต่งเฟืองหลัง Wolf Tooth สำหรับ Shimano 42 ฟัน
Tech Specs:
•These are specifically designed for use with Shimano cassettes. The clocking,
  or rotational orientation, between SRAM and Shimano cassettes is 
  much different so optimal shifting cannot be achieved unless the design
  is optimized for each separately.
•Design and manufactured in Minneapolis, MN USA
•Material 7075-T6