With this legendary single gear, Wolftooth kick-started its production into the form we know today. The derailleur is made of durable and lightweight aluminum that, thanks to the Wide/Narrow tooth profiling, will last far more miles than competing derailleurs from other companies. Fits all brands of 104BCD handles. the 30 tooth version contains direct threads for the chainring bolts and therefore requires the use of 10mm Drop-Stop A is only for 9,10,11 spd chains of all brands and for 12 spd Sram Eagle, KMC, Connex and Wippermann Weight: 30t - 36g | 32 - 47g | 34t - 56g | 36t - 60g | 38t - 66g Material: 7075-T6 aluminium Made in USA