Li-Ning Feidian 4 Ultra Marathon Racing Shoes

The Li-Ning Feidian 4 Ultra is a high-performance marathon racing shoe designed to enhance speed and efficiency for elite runners. Here's an overview of its features:
Speed Curve System: This innovative technology is designed based on observations and analyses of marathon runners, particularly addressing the changes in running posture and force application points during the latter half of a marathon. The system includes a dynamic dual-lever system with two curved structures, enhancing propulsion and support by adjusting the shape of the carbon plate and its integration with the midsole foam.
Midsole Technology: The Feidian 4 Ultra features Li-Ning's BOOM technology in the midsole, which is a supercritical beaded PEBA foam known for its lightweight and high rebound properties. The midsole also includes a curved carbon fiber plate designed to accentuate the rebound at the forefoot push-off.
Outsole: The outsole utilizes GCU (Ground Control Unit) rubber, which offers excellent traction on various surfaces. The coverage is primarily at the forefoot, with a unique traction pattern.
Upper: The shoe's upper is made from a lightweight engineered mesh called Boom Fiber, which ensures optimal ventilation and comfort during races.
Fit and Comfort: The Feidian 4 Ultra is designed to fit well, with minimal tension required on the laces, providing a secure and comfortable fit.
Performance: The shoe is described as a "rocket ship," offering a responsive and energetic ride. It's particularly noted for its forefoot rebound, which is described as "deep, dense, and energetic springiness."