The Nago Evo is a unisex semi round saddle ideal for medium to long distance road and XC riding. It offers great versatility for riders that like a choice of riding positions. It's equally suited to weekend rides and racing.Specifications:Size (mm): 278 x 134 - 278 x 141Weight (gr): 215 - 221Base: Carbon Fiber InjectionRail: TiroxCover: MicrofiberPadding: Light foam - Active DensityTechnologies:TiroX: Lightweight alloy steel rail. This is an aerospace grade metal with a high resistance to traction and torsion. Well suited to the stresses of a performance saddle it offers a good alternative to carbon Nack rails. It has 7mm rail clamp diameter.ESD: Ergo Shape Design: This is a refined saddle shape developed as a result of biomechanical studies done by Prologo over several years. ESD saddles feature a slender front area and a short rear area that quickly reaches maximum width. This permits a round pedal stroke allowing the rider to maintain a natural position. The legs of the cyclist have more space during all phases of the pedal stroke reducing friction and increasing alignment and performance. Finally the opening swift of the rear part of the saddle helps the rider to find the correct support and support of the ischial bones. This prevents sliding forward and any rotation of the pelvis.Active Density: This is the combination of different densities of foam and different rigidities in the base of the saddle for optimal comfort and performance. At the rear the foam has a higher density for stability. In the centre the foam is of lower density giving maximum comfort to the perineal area where pressure peaks can occur. In the tip of the saddle the foam has a lower density which allows a pressure reduction during maximum thrust. The Carbon Fibre Injection base also has variable rigidity providing stability at the rear and comfort in the middle and front. Furthermore the special openings in the hull make the base of the saddle more elastic to provide extra comfort when pedalling in a relaxed position whilst providing great stiffness during the phases of maximum thrust.