The Box One Brake Arms are cold forged & CNC-machined from 6061-T6 aluminum. Cold forging produces the strongest, stiffest, lightest weight & most durable bicycle parts. Both sizes feature 35 millimetres of vertical brake pad adjustment—more than most linear-pull brakes. Other features include precision sealed bearing pivots, titanium & stainless steel hardware, a flexible cable noodle & streamlined cable fixing point.