Yes, you can actually fill this bag with WATER and it will not leak! Unless you turn it upside-down, of course. ;)
Just like any other wet bag on the market that is closed with a zipper, large amounts of liquids would squeeze out through the zipper teeth, or through the drawstring opening.
However, we've been selling The Sweat Mate as a solution for 15 years, and we've never had a single one leak. And, we are still PERSONALLY using the same bags we made all that time ago.
We stand by our manufacturing; if you are not satisfied in any way, we'll make it right.