Child-sized stand-up potty seat, compatible with inner diameters of 175-225mm, GOOD DESIGN award winner. - Brand: Combi - Product Name: Stand-up Potty Seat - Size: Inner Diameter: 175-225mm, Outer Diameter: 260mm or more - Design: Gray - Features: GOOD DESIGN award winner - Material: Polypropylene Thank you for viewing. I purchased this for my child and used it twice, but they didn't seem to like it, so I'm selling it. Sterilized. Instruction manual included. Personally, I thought the shape would prevent urine leakage from the gap in the toilet seat, and the non-slip feature made it seem safe to use.