Commercial grade Dual Use Strength Range from Impulse Fitness The Impulse Dual Use Leg Extension & Leg Curl machine is part of a commercial grade Dual Use Strength range that allows for using one machine to perform two key exercises & thus save space in the gym. Due to combining leg extension & leg curl exercises the machine provides effective workouts that allow for building hamstrings or developing muscles of the upper thighs. Its generous weight stack of 113kg (250lbs) allows for very challenging workouts for both beginners as well as more advanced users. The machines stylish silver frame provides a very solid construction.