Prologo x zero cpc nack mtb saddlea flat saddle for short to medium distance riding where a frequent change in position is necessary 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