This replacement seatpost for the Tarmac SL7 ensures the perfect fit with two different setback options—0mm & 20mm. FACT carbon construction & aerodynamic profile compatible with the 2021 Tarmac SL7 Setback: 0/20mm Sleek Di 2 integration hides the Di 2 junction box inside Cylindrical aluminum head assembly adjusts fore-aft & tilt with an easy-access single bolt