These YogaAccessories (TM) Unfilled Sandbag for Yoga and Pilates – Maroon are often used in both yoga and pilates to deepen stretches by placing the sandbag on your knees during seated poses, on your thigh in a kneeling pose, or to stretch your arms behind your back. Why pay the high costs of shipping 10 pounds of sand, and then be stuck with a 10 pound bag that may not be the correct weight for you? YogaAccessories™ Unfilled Sandbags contain a unique, double-zippered, leak-proof system so that you can easily fill the sandbags with any dry item such as sand, beans, wheat, corn, or rice. You can then adjust to your desired weight. Having both a zippered inner liner and a zippered outer liner prevents leakage. The outer liner can easily be removed and washed.