The Terraframe 50 is a specialized backpack from Mystery Ranch that has an Overload feature that allows the wearer to secure abnormal loads and adds 30-60 Liters to its capacity. This is great for SAR‚ backcountry medics and pretty much anyone who wants the ability to carry an excess of equipment. Buy here: https://www.avantlink.com/click.php?tt=cl&;merchant_id=dd2bb191-351c-479c-9877-7efa128a6335&;website_id=43cb08ae-7b48-44d4-944f-7d827174d15a&;url=https%3A%2F%2Fwww.mysteryranch.com%2Fterraframe-3zip-50-pack