The flexible Racktime solution for sports bikes: This seat post mounted rack can be easily and quickly fixed to all standard seat posts, thus opening up the entire Snapit world. Optional side supports allow mountin of laterally fixed panniers to the seat post rack. Caution: not apporved for carbon seat posts! Caution: not compatible with Boxit, Child Seat Adapter or Heavy Duty Snapit Adapter. W: 650 g / 22.9oz. maximum load: 10 kg / 22 Lbs. Tube diameter: 10 mm / 0.04in.