Musher checkpoint bag is big and sturdy, made for excursions that require a significant amount of gear. The bag can take a beating, made with a though material and heavy-duty zipper. There are compartments on the inside. The bottom is a PVC material, making it easy to drag on snow. The bag is designed to hold checkpoint supplies in long-distance dog sled races, where mushers need to refill the sled before starting their next leg.