Compatible with Cannondale SystemSix models T1000, T2000, T400, T500, T600, T700, T800, and T900. It can be adapted to most standard bicycles, making replacement convenient for riders of different bikes. Please verify your bicycle seat type before ordering and select the appropriate installation style. materials for comfort and durability Made of PU leather with good breathability, soft to the touch and waterproof. Edges are precisely stitched for longevity. Interior features density memory foam for elasticity and support, effectively buffering vibration to deliver a comfortable ride. Breathable design and enhanced shock absorption Ventilation slots in the middle of the seat surface promote airflow between the body and the saddle, helping to reduce stuffiness and discomfort. Bottom of the seat includes shockabsorbing balls that flexibly respond to impact from different directions, further improving shock absorption. Ergonomic design for comfortable riding Front end is designed to be relatively narrow to avoid restricting thigh movement and reduce friction. Rear end is widened and features an ergonomic decompression groove aligned with perineal anatomy to relieve pressure and prevent compression of sensitive areas. 23 practical use scenarios Long endurance rides on a Cannondale SystemSix or similar bike: improved vibration damping and perineal relief for hours in the saddle. Daily commuting across mixed surfaces: breathable, waterproof cover helps keep you comfortable and reduces moisture buildup. Regular training on rough roads or cobblestones: memory foam comfort combined with directional shock absorption for steadier, more comfortable performance. Notes Confirm your seat type and choose the correct installation style before to ensure compatibility.