Feature:1. You can install it on the bicycle seat, can reduce air resistance, perfect for bicycle.2. Bicycle water bottle seat adapter, made of high quality aluminium alloy, steady, and durable.3. Can carry one or two water bottles, perfect for long time riding or long distance travel.4. Ultrahigh toughness, will not have a strong influence on deformation and fracture.5. Comes with necessary fittings, only need to fix the bracket on the back of saddle, easy to install.Specification:Item Type: Bottle Holder AdapterMaterial: Aluminium AlloyColor: BlackSize: Approx. 8x8x6.5cm / 3.1x3.1x2.6in .Package List:1 x Bottle Holder Adapter4 x Screw4 x Nut1 x Socket Head WrenchNote:1. Please allow 1‑2in error due to manual measurement. Thanks for your understanding.2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.