Yoga wheels are a relatively new aid starting to gain traction in the yoga world. These wheels are roughly 12 inches in diameter. When set upright, you can lie back on the wheel or place a foot or hand on top of the wheel to deepen your stretches and enhance flexibility, slowly rolling the wheel farther as you relax into each stretch. Wheels can also be used in more advanced practices as a way to challenge stability or to offer support during challenging poses.