The Monark 818E is a self-generating upright bike. Upright bikes are great for fitness as well as rehabilitating athletes from knee and hip injuries. This bike works like a typical exercise bike. There is a brake that creates the resistance/tension of the bike. It has a comfortable seat which is adjustable to accommodate a wide range of user heights. The handlebars will adjust to create a more comfortable riding experience. This Monark Fitness Testing Cycle is a self generating unit and runs only when you use it. This Monark Fitness bike is a popular choice of cardiac rehabilitation settings as well as fitness testing centers in health clubs. Overall, this it is a very well built machine for health club use, corporate fitness centers, or a busy home gym setting.