1x series chain device developed with world cup powerhouse adam craig the 1x is purpose built for cross country riding with a 1x9 drive train if you are running 1x9 and dont need a bash guard this is the ticket no more homemade contraptions needed 32 36t 58 grams 32 40t 62 grams black or white upper guide chainline adjustment bb mount only includes spacers for fine chainline adjustability looks and works great with a new mrp chainring