The uneven bars are an event for women only.  Each bar is 8 feet long.  The high bar is a little over 7 feet, and the low bar is almost 5 feet.  The bars can be adjusted for people who are taller or shorter so that they can safely use them.  Both of the bars are made out of fiberglass with a thin layer of wood, and held up by a medal base.  Cables support the apparatus so that it doesn't sway.

Each gymnast has their own routine on the uneven bars.  Every routine starts with a mount, or a way to get on to the bar.  Once you mount the bar, you do a series of flips, swings, and turns, on both the high bar and the low bar.  At the end you do a dismount, or a way of getting off of the bars.  Points are taken off of a bar routine for falling, bent or arms, or bad form.  

Gymnasts usually use grips to get a better grip on the bar while performing difficult moves.