What is a Super Sack? Imagine a heavy-duty, easy-to-handle bag that holds a full cubic yard of your chosen material — that's a whopping 27 cubic feet! Our Super Sacks are made from high-quality polypropylene, a stress-resistant, lightweight material designed to stand up to the elements and keep your supplies dry. With a duffle top to protect your materials from rain or wind, a spout bottom for easy and controlled material release, and corner lift loops for quick handling, these bags are designed with your convenience in mind.