Specification: Material: 3K Carbon Fiber Surface Finish: Matt Diameter: 7.2-7.4cm Net Weight: 25±1.5g Superior Material: bottle cages are made of 100% 3K Carbon Fiber,non-deformable, corrosion resistant,extra strength and durability combined with low weight ( only 25±1.5g ), effectively reduce the weight for long-distance travelers. Excellence Design: With smooth edges, will not hurt your hand and kettle. Matt Black shows composed personality, and brings you full sense of sports. Fits most Standard sizes Water Bottles: This bottle holder fits most standard sized water bottles and adjustable oblong mounting holes.The bottle cage is around 2.83 inches (7.2cm) in diameter, fit bottle dai 2.83-2.91 inches (7.2-7.4cm),bottle too big or too small may not fit firmly. Package include: 1*Bottle Cage with 2*Screws or 2*Bottle Cages with 4*Screws