They are for exclusive use indoors and for very short distances . As a general rule, although there are different models, the interior walker has two front wheels and the back is supported by two rubber tacos or ferrules, this makes the walker stable and safe to the person who wears it. If this walker was used in outdoor areas, there is a risk that in a few days, the ferrules or studs will wear out and replace them. Interior walkers are ideal for use in homes or residences. There are also models of walkers with a seat .