Reinvented,the new Terrain Master delivers when the going gets tough. Ideal for rough,muddy,sandy or snow covered trails. The Terrain Master has a tough steel frame,powder coated for durability and sports a machined aluminum rim with a stainless steel hub. We?ve also upgraded the all-terrain tire to a larger tire with both greater diameter and width,giving the Terrain Master even more capability on soft surfaces while providing enhanced patient comfort; all at a great price point. The Terrain Master is a superior device in both quality and functionality.