The difference between solid tire and pneumatic tire.
Scooters with solid tires ----- Kugoo S1, Kugoo S1 pro, Kirin S1 and ES2
Scooters with pneumatic tires ------ Kirin B1, kirin S1, kirin ES2, Kirin M4, Kugoo M2pro, Kugoo G booster and Kugoo G max
Solid tire has the advantages of long service life and low deformation rate, which reduces the maintenance cost of the vehicle. It is pretty hard, so it will not get punctured.
Being inflatable, pneumatic tire is capable of absorbing shock better and it normally weights less than solid tire.
There is no inner tubes inside solid tires.
Pneumatic tires come with inner tubes.
Following is the link to buy tires.