8.5 inch (8.5") air tire, 8 1/2 x 2 ("eight and a half by two"), 8.5 x 2.0 ("eight point five by two point zero"), 50-134, pneumatic. Measuring 8.5in (22cm) this tire is commonly referred to as an "eight and a half inch tire". Direct replacement for SHOK Scooters Neutron kick scooter (years 2021-2022) as well as many other brands and models such as Segway and Xiaomi.