Yeezy Foam Runner 'Onyx' gives the futuristic slip-on a sleek monochrome finish. Black injected EVA foam is used on the upper, which features sculpted lines and strategically placed vents that increase airflow. The heel provides a snug fit, and the top layer of the footbed is soft and supportive. An outsole with wavy traction ensures sure footing on wet or dry surfaces thanks to the lightweight construction.