Keiser's Air250 Leg Extension machine was carefully designed to make entry into the machine easy. It will accommodate a wide spectrum of users from 4' 10" to 6' 8" (1.47 to 2.03 meters). Leg cushions and seat backs are fully adjustable, without getting off the machine. The seat back adjusts forward and back without changing its tilt, protecting the lower back during the exercise. The hand-grips house the thumb buttons for convenient control of resistance while exercising. An optional range limiter is available to adjust the starting position from 20" to 120" of knee flexion.