I went ahead and got this after reading the reviews, knowing about the cardboard insert, knowing some leak, hoping I get a "good" one.  After carefully removing the cardboard insert, I was preparing to do the "sink test", when I noticed one of the seams was split, creating a small hole for water to enter.  After reading the reviews, it seems to me this happens a lot!  This is very flimsy plastic with fragile seams.  The seams easily split open.  The plastic is so thin (like plastic wrap), I fear car keys will poke a hole in them (I bought this specifically to hold rental car keys while snorkeling on vacation).  The mechanism at the opening which is designed to keep out water seems to work.  No one complained about water getting in at the opening. So it seems to me that Kwik Tek would have a great product if they used stronger plastic which was seamed properly to go with their awesome watertight lock.

Update:  I purchased the Lewis N. Clark Waterproof Multi Purpose Pouch, and it is a far superior product!  Heavier weight plastic, larger so it holds more, better seams, still floats, and best of all is rated waterproof to 9 ft. Get that one and save yourself the grief.
I went ahead and got this after reading the reviews, knowing about the cardboard insert, knowing some leak, hoping I get a "good" one. After carefully removing the cardboard insert, I was preparing to do the "sink test", when I noticed one of the seams was split, creating a small hole for water to enter. After reading the reviews, it seems to me this happens a lot! This is very flimsy plastic with fragile seams. The seams easily split open. The plastic is so thin (like plastic wrap), I fear car keys will poke a hole in them (I bought this specifically to hold rental car keys while snorkeling on vacation). The mechanism at the opening which is designed to keep out water seems to work. No one complained about water getting in at the opening. So it seems to me that Kwik Tek would have a great product if they used stronger plastic which was seamed properly to go with their awesome watertight lock. Update:  I purchased the Lewis N. Clark Waterproof Multi Purpose Pouch, and it is a far superior product! Heavier weight plastic, larger so it holds more, better seams, still floats, and best of all is rated waterproof to 9 ft. Get that one and save yourself the grief.