The Karman Healthcare Universal Adjustable Cup Holder is suitable for most wheelchairs and walkers. No tools required to install the cup holder onto a frame with a diameter of either 7/8 inch or 1 inch, or a maximum of up to 1.75 inches in frame diameter. Featuring an adjustable mouth for beverages up to 2.75 inches in diameter. The Cup holder is sleek, easy to install, and a great accessory for any wheelchair or walker user.