As a part of the cross country minded Tundra family, the Fizik Tundra M5 VS K:ium Saddle was built with a focus on weight and efficiency, much like Fizik's renowned road saddles, with added attention to comfort apparent with its Versus distinction. The Tundra M5's race ready silhouette is slim and tapered, just 125mm wide and 290mm long, aiming to accommodate riders with narrower sit bones who need room to move around in the saddle as they constantly anticipate terrain changes during a race. Fizik enhances rider comfort by adopting a pressure relief channel along the center of the saddle, and unlike many saddles with splits or cutouts, the channel does not affect the overall stiffness and rigidity of shell. The carbon reinforced nylon WingFlex shell does flex, but it does so specifically along the wings of the saddle only it flexes just enough to allow riders of different sizes to maintain freedom of movement throughout the pedal stroke without experiencing chafing or irritation, while the rest of the saddle body stays rigid. Fizik surrounds the center channel with soft, low density cushioning for a more forgiving, but not overwhelmingly plush, ride, and covers the entire saddle shell with a mix of Microtex, Anthracite, and Cordura nylon. Atop K:ium rails, the saddle won't absorb as much vibrations as its pricier carbon siblings, but it will still maintain excellent durability and resistance to wear from the elements without adding unnecessary grams to your ultralight XC frame.