The inside diameter is 1-1/8 inch, The bottom is about 2 inches outside diameter. Made of durable TPR rubber and reinforced with metal insert for skid-resistant traction and longer wear time. Ideal replacent tips for just about any item usde in the bathroom-universal compatibility fits most bath benches, Shower Chairs. Its unique angled legs with non-skid rubber tips allow users' weight to be distributed over a larger area making the shower chair ultra- safe and stable. Tool-free assembly makes it easy for any one in the family to assemble for use within minutes. These replacement tips are designed to perfectly fit any brand bath bench and are designed to not only add but are quick and simple to replace your old tips Fits any brand 1-1/8inch tubing. TPR rubber is durable and corrosion proof. Its unique angled legs with non-skid rubber tips allow users weight to be distributed over a larger area making the shower stable. Wider tips with convenient drainage holes help deal with areas with excess moisture, Unique big drainage holes improve the overall sitting experience and also allow water to be drained effectively thereby reducing the risk of slippage.