ACG means All Conditions Gear. And that means gear built for exploring. The Zoom Air AO does it all with tough traction and a drainage system built for treks through trails and water. Zoom Air cushioning in the heel delivers a soft response with every step, while sticky rubber throughout the midfoot provides optimal traction. This product was designed and tested in Oregon, USA. The state's vast wilderness and climate served as inspiration for the shoe's look and purpose.