The use of chemicals is an option. Plus you can set the appliance to steam-only (no need for chemicals), wash mode or a mix of both (chemicals will help with cleaning in this case).
The Select does not come with wheels (which is a joke, as the mounting device is included). Also, only the wide and the very narrow brush are included in the scope of delivery (the Pro comes with a medium width brush)
That's it... same device, different name ¯\_(ツ)_/¯