Metal-free - no problems with security checks. Upper material is a combination of microfibre and textile. The lining features Gore-Tex Extended: a 3-layer Gore-Tex laminate that is waterproof and highly breathable. The abrasion-resistant lining material offers maximum climate comfort, especially for flexible use indoors and outdoors and in warmer temperatures. The insoles are comfortable, cushioning, moisture-absorbing and antibacterial. A separate heel cup provides good cushioning and foot guidance with "Airflow" channels. The "Perfect-Fit" labelling makes it easy to check the correct shoe size. The non-slip properties ensure very good grip on different surfaces thanks to the tread design and the special rubber used. The sole is flexible, lightweight, metal-free and puncture-resistant. The modern, lightweight sports shoe sole construction has a rubber/PU tread.