asymmetric bars 
plural noun
A pair of bars of different heights used in women’s gymnastics.Behind the asymmetric bars sat the gymnasts, a rainbow of tracksuits under a canopy of national flags....
- The 15-year-old, who has just returned after an injury-riddled three years, made a stunning comeback to the arena when she claimed a silver medal in the asymmetric bars competition.
- The reigning Olympic asymmetric bars champion had suffered mishaps in Atlanta and Sydney and Athens was her final chance to clinch the all-round title.