parallel bars

from The American Heritage® Dictionary of the English Language, 4th Edition

• n.pl. An apparatus for gymnastic exercises consisting of two horizontal bars set parallel to each other in adjustable upright supports and used mainly for swinging maneuvers.

from Wiktionary, Creative Commons Attribution/Share-Alike License

• n. A set of apparatus consisting of two horizontal bars at a small distance apart, used by male gymnasts, upon which acts of swinging and holding and jumping are performed.
• n. A gymnastics event using the parallel bars.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• n. gymnastic apparatus consisting of two parallel wooden rods supported on uprights