Its a small section inside the shoe that can expand up to 5 millimeters to prevent numbness. Without any extension system, the toes end up on top of each other and tend to get numb.
Shoes - Gear - Women
Triathlon Shoes — Playtri
Shoes - Gear - Women
Triathlon Shoes products
Louis Garneau Womens Tri X-Speed XZ Shoes
Gear - Women Louis Garneau
Shimano SH-TR9 Cycling Shoe - Women's - Bike
Shimano SH-WT60 Cycling Shoe - Women's - Women
Louis Garneau Pink Tri X-Speed II Cycling Women's Size US 9 Euro
The Sidi T-5 Air is designed specifically for triathlon. The upper weathers rain and water without losing stiffness, and the closure system is easy to adjust and reliable, the T-5 Air is particularly suitable for giving your best during triathlon competitions.
Sidi Women's T-5 Air Cycling Shoes - Rose Red White - 39
Louis Garneau Tri X-Speed III Triathlon Shoes - Women's
Shoes - Gear - Women
Lake TX213 Air Tri Shoe - Men's - Men
Whether you ride with an SPD system or standard road bike pedals, the Tri X-Speed IV fits them both. No matter if your feet are thin, medium or wide, Garneau's X-Comfort Zone technology prevents numbness by extending the shoe's edges if needed. A wide foot entry makes it easy to perform those first hop-on-the-bike transitions, and 2 hook-and-loop straps help to attach your feet and start pedaling in no time.
Louis Garneau - Men's Tri X-Lite III Shoes, Drizzle, 47
Louis Garneau Women's Triathlon Shoes & Accessories