Review on Waterdrop Gravity Water Bag: Portable Foldable Bag for Backpacking, Camping & Emergency - 1.5 Gal, Compatible with Water Filter Straw by Jerry Forehand

I bought this for a beginner scouting tour I was teaching. This is a heavy duty bag that comes with a carry strap and tube. It was a pleasant surprise. The tube fits my Sawyer mini perfectly. The carry strap worked well for junior scouts who would otherwise have trouble carrying a full hydration bladder. The scouts easily filled this bubble at the nearest lake and made their way back to camp. We've also used it in shallow water, but they didn't do a good job of avoiding sediment clogging the valve at the bottom. Good lesson moment. This is a GREAT, SUPER EFFECTIVE gravity filter. Just add Sawyer mini and you're done. Absolutely no leaks. I now recommend this to all our Scout families.