The Rambo Beverage Holder is intended for use with cylindrical shaped water bottles - hence tall boys fit fine! The bottom strap is very adjustable, allowing the cup holder to accommodate 12-24oz containers. The inner layer wraps your beverage with a cozy microfiber that won&';t scratch your bottle. The outer layer is crafted of a badass bombproof nylon for long lasting use, with an elastic band that allows for varying bottle sizes. In between these two layers is a rigid but flexible plastic liner that provides a firm holder, meaning it will never lose its shape. Three points of attachment fasten to your stem, handlebars, and steerer tube for a solid hold, providing carefree riding and sipping on the beverage of your choice.