PROLOGO Scratch Pro X14 Tirox Saddle Prologo Scratch Pro X14 Saddle with Tiro X Rails. This saddle is a round saddle so suited to long mountain bike rides, the Tiro X rails add a great combination of strength & light weight support. This saddle uses Prologo's ' Round' saddle shape that gives the rider a more comfortable seating area on long rides with the weight being shared equally throughout the saddle. Technology: Tiro X Rail: Ti 1.4: Rail light-alloy steel, this material is highly resistant to traction, & torsion for its light weight it’s 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 doesn’t 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: Mu