The FitBar Grip Wheel works like a rotating pull up bar, except the left and right grips are independent of each other. Each triangular element rotates about a common shaft, and included three foam grips each. Each foam grip covers a metal tube that rides on bushings to allow it rotate freely. The challenge with the Grip Wheel is that you are always supporting your body weight, and momentarily supporting your weight from one arm as the other reaches for the grip. It requires upper body strength and core strength to keep your body stabilized under the Grip Wheel, preventing it from swinging from side to side. Overhand grip and underhand grip can be used to spin the grip elements. You can also straddle the Grip Wheel to emulate the Spartan Twister obstacle. The Grip Wheel is an excellent training tool for OCR athletes, ninja course warriors, and anyone looking for a dynamic rotating upper body workout. Made in USA.