This is a large sized cup holder meant specifically for use with an electric wheelchair. As a larger sized cup holder, this product is meant to be used with larger cups such as mugs or canned drinks with an insulated sleeve (also known as a coozie). Using the SnapIt! System, this cup holder easily mounts under your electric wheelchair's armrest. The top ring of the cup holder is reversible to allow for both left and right hand applications. Be sure to specify your electric wheelchair's specific model when you order. This larger sized cup holder has an inner diameter of 3.62" and an overall height of 3.95."