About Avid BB-5 Mtn Mechanical Disc Brake: For use with linear-pull brake levers (sold separately). Tri-Align Caliper Positioning System (CPS) for caliper/rotor alignment. Monoblok® 1-piece caliper with Ball-Bearing cam mechanism. Addition of barrel-style pad/cable-tension adjuster at housing stop. Inboard pad adjuster knob and pad retraction for drag free setup. Tool-free pad adjustment and replacement (unique pad for BB-5). Includes: post mount (74mm) caliper with International-Standard (51mm) fork or frame adapter; Roundagon 6-bolt/44mm-BCD 160mm rotor; and BB-5 specific disc pads.