New Black Mountain Products Speed Jump Rope. Each Jump rope is made of a steel cable for precision jumping. Both handles are adjustable to fit everyone and every size. BMP jump ropes are 10 feet in length. Each cable is made with a lightweight design and is portable. Jump ropes are an excellent cardio exercise. Jumping rope can increase your cardiovascular muscles, as well as strength and endurance. Jump ropes benefit athletes, adults, children and anyone looking to get in shape.