The robot standard wheels are 70mm wide, made of plastic. There is an option to use narrow wheels if you have narrow aisles in your stables. These narrow wheels are 35mm wide which means the robot will be 70mm narrower in total.

If your robot has the 35mm wheels you should know that it could effect the friction against the floor due to less contact area, specially on very dirty floors (the wheels slipping, leading to incorrect position).

Since the robot gets 70mm narrower with the 35mm wheels it could effect the balance of the robot sideways when it washes far out with the telescope combined with uneven/sloping floors.

Flexi-wheel 70mm = 680mm wide
Flexi-wheel 35mm = 610mm wide

For help with the choice of wheels, please see Aisle and robot measurements