Made of AL7075 Aluminum Alloy CNC-machined,Smooth surface,Rust-proof.
Bracket turns 90 degrees to suit mounting position.easy to install and remove.
Fits for diameterof seat post: 30.9mm or 31.6mm,Hexagonal Spanners are included.
Fits for Handlebars diameter :22.2mm 25.4mm or 31.8mm,with single model you can Install only one bottle cage.With Double model you can Install one bottle cage in middle or two bottle cage on both side, but you can't Install three at once with double model.
please note This mode is one piece , but It can hold two water bottle on your bike once, not 2pieces in the package.