Dual Ab Wheel for Abs / Abdominal Roller Workout Exercise Fitness Great for adding muscle in the chest, shoulders, back and arms. Ab toner has two non-skid wheels for extra stability. Textured easy-grip handles. Work shoulders, arms, entire back, and all sections of the abs. Fits all fitness levels. Defines core muscles. Lightweight, portable dual-wheel design increases stability. Contoured, rubber hand grips ensure safety and offer comfort Rubber covered wheels for safety