When every second of a split counts, efficient power transfer is key. The T-5 Air's Twelve Carbon Composite sole, with carbon-injected nylon ensures energy isn't lost to a supple sole, and is comfortable enough for the long training miles that lead up to the main event. The T-5s reinforced heel cup withstands pressure from use, while the soft lining ensures sock-free comfort. Sidi's hallmark ratcheting system would be too slow for quick transitions, so the T-5 uses a two-strap closure system and overlapping upper design. The straps have a grippy finish which makes them easy to adjust on the fly, even with hands wet from the swim. An oversized heel pull-tab makes pulling on the shoe as fast as possible while you speed away from the transition zone.