Specifications: Product name:Bike cup bottle holder Material: Aluminum Alloy Color:Black Dimensions: 5?(L) x 3.4?(W) x 1.0?(H) Inside Diameter of Cup Clamp: 3.0" Weight:68g Compatibility: Fits 25mm (1.0") diameter handlebar Installation: Clamp uses 1 hex bolt. Use 5mm or 5/32? hex wrench/key to tighten (not included)