Prologo nago evo pas tirox saddlethe nago evo pas saddle with tirox rails is a really technical saddle with a semi round profile its suitable for medium to long riding and is backup with the great support from light pu padding and tirox rails shape semi round end use road learn 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 aviatio