Xlab delta sonic mount gorilla xt cagethe delta sonic allows the bottle to be close to the saddle hiding in the riders draft and provides clean air flow working closely with cervlo and their wind tunnel testing results xlab developed an aerodynamic single rear system specific to ritchey clamp seatposts with a 10mm horizontal rear hole featuresreliable customizable the delta sonic fits snug into the seatpost providing a sturdy non sway bottle mount for fast and safe access to your bot