The xlab delta sonic saddle bottle cage allows the bottle to be close to the saddle and hides in the riders draft to provide a clean airflow and not negatively affect the aerodynamic properties of the ride the xlab delta sonic saddle bottle cage fits snug into the seat post providing a sturdy non sway bottle mount for fast and safe access to the bottle the delta sonic rod can slide along the seat post for a customised fit xlab recommends a 1 insertion minimum into the seatpost compat