This is your entire wheel kit, not just the rubber tire. The wheel assembly is a genuine Segway part and its size is specific to your i2 Personal Transporter’s software. The non-marking traction controlled tire diameter is 19″(48 cm) (100/65 R14) and mounts on a custom i2 rim. Its tread pattern and rubber compound have been specifically selected to provide traction on a variety of terrain. Segway requires that PT riders use only genuine Segway wheels and tires given that they are an integral component of your PT.