Rehabilitation Advantage Clamp-On Wheelchair Cup Holder is a great accessory for most wheelchairs, walkers, rollators, scooters, chairs and more. This cup holder allows you to keep both hands free to prevent unwanted spills. This simple item makes traveling with liquids much easier. Once completely tightened, this cup holder will stay secured. This cup holder can be attached to a variety of places. It will accommodate cups, bottles, mugs, or cans. It includes a small tube adapter for smaller size tubing. This cup holder works with 7/8″ to 1″ tubing. The inner diameter of this cup holder is 2.75″. Overall, this clamp-on cup holder was designed to add convenience to your daily routine. Purchase yours today!