The Post-Lock is a rear-mounted rack attachment that can be positioned directly on a seat post to provide a secure mounting point. Features: This is not a seat collar and cannot be used to keep your seatpost in place Not for use with carbon fiber seatposts Please consult your seatpost manufacturer to check compatibility Max torque 3 - 5 N-m 34mm-wide rack mount threaded for M5 bolts Stainless steel pivot and bolt Black anodized AL-6061 aluminum with laser-etched logo Specs: ColorBlack