Please do not get a walker. They are extremely dangerous and not good for children's bodies. Please look into an Exersaucer instead. Even thresholds between rooms (not just stairs) can cause them to tip, espcially is the walker is wider that the doorway. Here is some info from the Consumer Product Safety Commission:
The U.S. Consumer Product Safety Commission
(CPSC) warns parents that baby walkers are not
“baby sitters.” Always take precautions and watch a
child in a baby walker to prevent the child from tipping
over or falling down stairs and being injured
or killed.
CPSC estimates that each year there are 21,300
hospital emergency room treated injuries associated
with baby walkers for children under 15 months
of age. CPSC receives reports of an average one
to two deaths a year with baby walkers. Most of
the injuries were caused by falling down stairs.
Before putting a child in a baby walker, take several
precautions. Check for hazardous areas where
the baby walker might go. Block off stairways and
exit doorways. Avoid areas where there are uneven
floors such as carpet edges or raised thresholds
that may cause the walker to tip-over. Clear away
objects on tables, countertops, or stove tops that a
child in a baby walker might be able to reach. To
avoid burn injuries, don’t let a child use a baby
walker near ranges, space heaters, or fireplaces.
After putting a child in a baby walker, watch the
child carefully because a child can move very fast
in a baby walker.
A voluntary standard for baby walkers requires that
walkers carry warning labels with many of these
messages on them. The standard also requires a
separate warning label – easily seen when the
consumer places a child in the walker – instructing
care givers to block stairs and steps securely
before using the walker.
And from a child safety site:
Medical experts do not recommend the use of walkers. Injuries as serious as skull fractures, concussions and broken limbs can occur if the walker tips over or if the baby falls down a staircase. However, if you do use a walker, please be sure to use the following guidelines.
Close and lock doors to stairways and block staircases with gates. Explain to older children that leaving doors open is not safe when a baby is in a walker.
Use walkers only on smooth surfaces. Edges of carpets, throw rugs and raised thresholds can cause a walker to tip over.
Never leave a child alone in a walker.
In a walker, a baby may be able to reach more items in the room and may move around faster. Constant supervision is essential.