Set of 2. Develops dynamic core strength. Ability to tone the muscles of the entire midsection at once from a variety of different angles. With These twin wheels, you can do many exercises to strengthen entire upper body as shown in additional images. Allows for more push-up variations to target the upper body area. Improve flexibility through a series of active stretches. Strengthen and tone abs, back, shoulders, arms & chest. 

Double Core Strength Wheel Exerciser - Clearance