• Seat post length: 350mm. • Seat post diameter: 31.6mm. • Replaces used or broken seat posts, compatible with mountain bikes, road bikes, and MTB. • Made with aluminum alloy, resistant to wear and corrosion. • Easy installation: loosen the screw of the old seat, remove it, attach the new seat, and install it on the bike rack. • Includes safety line mark, insert at least above the minimum line. • Measure the size of the old seat post to ensure compatibility.