The Yeezy Foam Runner is a sustainable shoe designed by Kanye West and released by Adidas. It's made from a proprietary material called "Alv foam" which is an environmentally friendly, algae-based foam. The shoe features a minimalist design with a monochromatic upper, and a sole made from the Alv foam. It's a slip-on style and has a unique texture and feel. The shoe was released in limited quantities and was highly sought after by Yeezy fans and eco-conscious consumers. It is mostly available for a short period of time.