Parameters: The bicycle saddle cushion size:11×8.66 in (L * W); backrest size: 7.48*8.66 in (L * W); weight: 4.17ib. Manual measurement, slight inaccuracies may occur Installation Instructions 1: This backrest saddle is compatible only with seatposts(tubes) WITHOUT clamps; seatposts(tubes) with clamps CANNOT be installed, please check it carefully before purchasing Installation Instructions 2: Ensure the narrowest end of the seatpost—the end connecting to the saddle—has a diameter of 0.87 inches/22 cm (most bicycle seatposts meet this specification at their narrowest point). We recommend measuring before purchase Note: The saddle is equipped with high-quality mounting tools. After installation is complete, check that all screws are securely tightened. Suitable for tricycles, mountain bikes, road bikes, commuter bikes, electric bikes, exercise bikes, etc. Material: High quality carbon steel is used for the connecting part of the backrest saddle, and the cushion is made of high elastic latex material. The surface is made of high density PU, waterproof, dirty and wear-resistant THALOUS Bike Seat with Backrest Oversized Comfort Bicycle Saddle Replacement Soft Memory Foam Padded PU Cushion Universal for Tricycle Mountain Bike Commuter Bike Electric Bike