Arena Girls Powerskin ST 2.0. This Full Body Short Leg Open-Back technical swimsuit streamlines from shoulders to knees and is designed for both competition and swim practice. This is suit is FINA-approved and made of knit fabric and has a resilient lining. The sleek surface and built-in muscle compression improve speed in the water and muscle support. Plus the innovative seam pattern keeps the body lifted while swimming. As your young athlete speeds through the water, her upper-body will feel free and supported with the reinforced center strap. Finished with flatlock seams for optimal comfort.