YD04 Hollow Carbon Fiber MTB Road Mountain Bicycle Cycling Saddle Seat Cushion Black The YD04 Plastic &amp; Steel Mountain Bike Road Bicycle Hollow Saddle Seat offers a great option for bicycle seat replacement! It features a unique, ergonomic hollow design made with shock-absorbing technology. Smooth curves mold to your body and provide a good support. And it is built with a scale on the bottom frame for easy installation. Crafted from high-grade carbon fiber, it is tough and durable for long-lasting use.