Prologo x zero cpc tirox mtb saddlenew to the prologo range the x zero is for xccross country use this one has the new tirox rails stainless steel for a lower weight than the old ti 14 rails greater resistance and vibration absorbtion shape flatend use cross countrylearn more with the prologo buying guide featurestirox rail rail light alloy steel this material is highly resistant to traction and torsion for its light weight its for these reasons it is used in used in the aviation