1. Universal: Are you still worried that you don't have enough space or pre drill holes to install the water bottle holder? Our bicycle bottle holder adapter solves these problems. It can be installed on your bicycle handlebar, seat post, or frame. The folding mounting system is quick and easy. The adapter is compatible with most bicycles and water bottle holders. 2. Quality Sturdy Material: The mounting bracket is made of quality aluminum alloy with an anodized surface, ensuring sturdiness and durability. The bike seatpost adapter is secured with double screws, providing strong holding power to keep the bottle in place even on rough terrain, so you don't have to worry about it falling out while cycling. 3. Easy Installation: The bracket can be rotated 90 degrees to fit the installation position. It includes a bottle cage adapter with screws and an Allen key. This bike cup holder adapter also comes with 1 spacer and 1 rubber piece, allowing adjustment for mounting diameters ranging from 21 to 31.8 mm (0.83 to 1.25 inches). 4. Practical Bicycle Accessories: The package includes 1 x bicycle bottle holder adapter, 1 x adapter pad, 1 x Allen key, and 1 x rubber piece. Suitable for bicycles, walkers, wheelchairs, trolleys, pushchairs, scooters, camping, or travel. The dual bottle holder design ensures you stay hydrated during long journeys.