1 Dual Ab Wheel Roller Tone Six Pack Abs Abdominal Workout Gym Exercise Fitness New! This double wheel exerciser measures: 7 3/16 x 4 3/4 strengthen and tone abs, shoulder, arms and back. Two non skid wheels for added stability. The unit teams up a pair of nonskid wheels and two easy grip handles. To use, simply get on all fours, grab hold of the handles, and glide the wheels back and forth across the floor. At various points during the exercise, you'll work every major upper body muscle group as your torso adjusts to the movements. You do not have to spend a lot of time using the roller, a few minutes a day will strengthen your core.