Heavy Duty Sandbag Trainer Shell by FringeSport/Weight Bag for Training, Conditioning, Crossfit WODs, Military Training, Strength Training Heavy-duty Cordura construction Military-grade YKK zipper Works with just the shell, or the shell + fillers for a modular solution Small trainer comfortably fits up to 50lbs of weight. Large trainer comfortably fits up to 100lbs of weight. Does not include filler bags or sand. Heavy-duty Cordura construction -the same thing <span class="a-text-bold">military-issue</span> rucks are made of. The zipper (a common failure point) is a <span class="a-text-bold">military-grade</span> YKK zipper, which is protected by a Velcro closure. The seams are <span class="a-text-bold">double-stitched and box-stitched</span> at all stress points. Whole bag is <span class="a-text-bold">reinforced</span> with lashing. Works with just the shell, or the shell + fillers for a modular solution. Small trainer comfortably fits up to <span class="a-text-bold">60lbs of weight.</span> Large trainer comfortably fits up to <span class="a-text-bold">100lbs of weight.</span> Small Bag comes with two top handles (7.5&#034;) and two tabhandles (4&#034;). Large Bag comes with two top handles (8&#034;) and two side handles (4.5&#034;). Small trainer (top image) comfortably fits up to <span class="a-text-bold">60lbs of weight.</span> Small Bag comes with two top handles (7.5&#034;) and two tabhandles (4&#034;). Large trainer (bottom image) comfortably fits up to <span class="a-text-bold">100lbs of weight.</span> Large Bag comes with two top handles (8&#034;) and two side handles (4.5&#034;).