Nivia Track and field 400 The spikes have a breathable mesh upper to keep your feet cool and comfortable, with a lightweight TPU stitchless upper when the pace heats up. Asymmetrical lace design for snug fit, supportive tpu sole plate. ideal for a short sprint. TPU Fusion Technology in a hexagonal breathable mesh upper for long-lasting comfort. It creates a better, healthier environment for your feet to thrive in. The Fusion Technology construction produces an irritation-free fit, reducing bulk, layers, and weight for high breathable Hexagonal breathable mesh is light in weight and allows you to move quickly. Two layers of high-density foam line the collar and mould to the athlete's foot to create a personalised heel fit,adding soft support and custom comfort. The Die-Cut soft NR EVA sockliner is laminated with polyester fabric for additional cushioning. The soft cushion NR EVA inner insole improves cushioning and comfort. TF-400 features a forpart rapid agility soleplate, supreme energy return, and 7 removable spike pins of regulation length on each boot. The rubber sole on the back heel provides durability and traction on the track. suitable for mid-sprint events.