Many modern rollators are made from aluminium, which is a lightweight metal with excellent rigidity.
They are also fitted with high quality wheels, which not only roll smoothly but also rotate, making them highly manoeuvrable.
If space is tight, three-wheeled rollators are usually the best option.
While some compromise is made in terms of stability, it is made up for in ease-of-control.
Rollators with large wheels are better for overcoming more significant curb rises and other obstacles you might find on the street.