The Tristar Air Climber tones your lower body and strengthens your cardiovascular system. It has an LED display to indicate your workout time and the amount of calories burned. It uses air-power technology that lifts your legs without straining your knee joints to keep the workout going. This step exercise machine can hold a maximum of 300 lbs. It requires 2 AA batteries (not included) to get started. This air stepper can be wiped clean with soap and water.