Prologo Nago Evo Plus Saddle with Tiro X Rails: Prologo Nago Evo Plus Saddle with Tiro X Rails is a really technical saddle with a semi round profile its suitable for medium to long riding, & is backup with the great support from Light PU padding & Tiro X rails. Tiro X Rail Rail light-alloy steel, this material is highly resistant to traction, & torsion for its light weight its for these reasons it is used in used in the aviation & aerospace industry. Tiro X then turns out to be a rail with a good balance between weight & strength, that doesnt fear the normal stress that addresses a bicycle. ESD Ergo Shape Design is where Prologo have trimmed the saddle at the sides meaning more space for the legs of the cyclist, this translates into a better pedal stroke & the rider staying in the correct position. Active Density Multiple padding zones along the saddle. High density at the rear, medium in the middle & low at the front, this gives the maximum level of comfort where its needed & eliminates pressure during pedal strokes. Tiro X Rails Micro Fibre Cover Carbon fibre injection saddle Ergo Shape Design